Results of Arthroscopic Bankart Repair for Shoulder Dislocation

Twenty years of open surgeries to repair unstable shoulders from dislocation have brought many improvements. Excellent results are reported and the recurrence rate has dropped. Now surgeons are doing some of these operations arthroscopically. In this report, results of the Bankart procedure done by arthroscope are compared to earlier results with the open technique.

The Bankart procedure is used to repair shoulder instability caused by torn ligaments and a torn labrum. The labrum is a rim of cartilage around part of the shoulder socket that helps hold the shoulder in place. If the tear extends up far enough, it will even pull some of the biceps tendon away from where it inserts into the labrum.

The Bankart repairs each of the soft tissues damaged by the dislocation. During arthroscopy, the surgeons repaired each damaged area of soft tissue. They used suture anchors to hold the biceps in place. The arthroscopic repair carefully mimicked all the steps used in the open approach.

Pain, motion, and function were used as measures of success or failure. Recurrence of shoulder dislocation was considered a failure. Patients were followed for at least two years. Pain decreased and motion and function improved for 90 percent of the patients. Ten percent had at least one or more shoulder dislocations after surgery.

The authors say the 10 percent recurrence rate is similar to the open Bankart repairs. They credit this success to using the same methods used in the open technique. Making sure that all injuries are repaired is a key factor in the success rate. Results were similar for collision athletes versus noncontact patients.

Two Surgical Methods of Acromioclavicular Resection Compared

Over the top of the shoulder a bony projection from the shoulder blade (acromion) meets up with the collarbone (clavicle). This joint is called the acromioclavicular joint (ACJ). The ACJ can become very painful when there is arthritis or impingement. Impingement occurs when tendons from the rotator cuff get pinched as they pass through the space below this joint.

In this study, surgeons from Columbia University Medical Center in New York compare the results of two different ways to surgically repair the problem. The first, more common method is the bursal or indirect approach. The second is the direct approach. In both methods, the end of the clavicle is cut and taken out where it meets the acromion.

Sixty-six shoulders in 60 patients were divided into two groups based on the method used to resect the clavicle. Each procedure is described by the surgeon. All operations were done with minimal incisions or openings using an arthroscope. Results were measured by level of pain, shoulder instability, and function.

The authors report the direct approach gives the surgeon a better view of the entire joint and easier access to the ACJ compared to the bursa approach. However, the direct method may damage the capsular ligaments above the joint. The patient can be left with instability of the remaining clavicle.

In this study everyone was followed for at least two years. Measures of function reported after the operation were equal in both groups. Ten percent of the direct group needed a second operation for instability or return of painful symptoms.

The authors conclude both ways to treat problems at the ACJ work well. The direct approach may be a little more risky because of the potential for damage to the joint capsule and ligaments. They advise surgeons who use the direct approach to repair any damage done to these structures right away. The supporting and ligamentous tissues must be protected during surgery in order to maintain ACJ stability.

Shoulder Problems in Overhead Throwing Athletes

Shoulder problems are common in overhead throwing athletes, especially baseball pitchers. In this article, posterior capsular contracture of the shoulder is reviewed in detail. The posterior capsule is a band of tissue across the back of the shoulder. It blends with fibers from the tendons of the rotator cuff, the four muscles that support and hold the shoulder in place.

The posterior cuff tightens up as the arm is lifted forward and rotates inwardly. It keeps the head of the humerus (round bone at the top of the upper arm) from moving too far in one direction.

Too much tension in the posterior capsule changes the way the shoulder moves. The head of the humerus can’t stay in the center of the socket like it should. There’s a loss of internal rotation, cross-body movement, and shoulder flexion. For a baseball pitcher, the loss of these three motions affects his or her throwing ability.

Two movements in the shoulder during the throwing motion are important for pitchers. One is called the glenohumeral internal rotation deficit or GIRD. The other is the external rotation gain or ERG. GIRD is the loss of internal rotation of the throwing arm. ERG is the amount of external rotation in the shoulder during the throwing motion.

The authors point out that whenever GIRD is greater than the ERG, the risk of shoulder injury goes up. They suggest that screening before and during each baseball season can help prevent shoulder problems for pitchers and other overhead throwing athletes. Tests of motion for this problem are reviewed in detail. Some simple stretches may be able to help prevent the need for surgery. The authors also review surgical techniques used for this problem and the rehab program following.

More Men At Risk for Pectoralis Major Ruptures

The pectoralis major muscle is the large fan-shaped muscle across the upper chest. It attaches in several places along the breastbone, collarbone, and to the front of the upper arm. Rupture of this muscle is rare but on the rise. Early cases years ago involved men being dragged by a cow during wild-cow milking contests. Today middle-aged male weight-lifters are at greatest risk.

Military orthopedic surgeons offer this review article for sports medicine or general orthopedic surgeons. They say most orthopedists will probably have at least one case of pectoralis major rupture. Understanding the anatomy and recognizing the mechanism of injury will guide treatment decisions.

Bench pressing is the most common cause of pectoralis major rupture. Other causes include wrestling, water skiing, football, and hockey. Less often, falling on an outstretched arm, injury during a car accident, or being hit by a heavy, falling object can cause the same injury.

The authors describe what to look for on exam with this type of injury. They present photographs and MRI images to guide surgeons in making the diagnosis. Treatment depends on the type and location of the tear.

Surgery is advised for most patients with complete rupture of the tendon. This is the only way to regain full strength. Delayed repair may present a problem when scar tissue or muscle wasting occurs. Surgery may not be indicated for older, debilitated adults in nursing homes or long-term care facilities. Partial tears of the tendon or tears through the muscle belly may recover with conservative (nonoperative) care.

The authors offer surgeons advice on both conservative care and various methods of surgical repair. Postoperative care includes protection in a sling. A program of progressive exercises is also prescribed.

Rare Case of Voluntary Poterior Shoulder Dislocation Followed By Trauma

In this report, surgeons from The Johns Hopkins University present a rare case involving posterior shoulder dislocation. A 17-year old male on the high school wrestling team dislocated his shoulder during a match. Most shoulder dislocations pop out of the socket in a forward direction. In this case, the dislocation was in the opposite direction (backward).

What made this case so unusual was the fact that before the young man’s injury, he could voluntarily dislocate both shoulders. He could also put them back in the joint without help. It’s unusual for anyone who can voluntarily dislocate the shoulder in a backward direction to develop instability of the joint after an injury.

In this case, after the wrestling injury, an MRI showed a large posterior tear of the labrum. The labrum is a rim of cartilage around the shoulder socket to help keep the joint in place. A tear of this type and in this location is called a reverse Bankart lesion.

The authors point out how important it is to have a clear diagnosis before treatment. Treatment for traumatic instability is different from treatment for voluntary shoulder dislocation. In this case, the patient had both problems.

Physical therapy and time to heal likely would not help the traumatic injury. Conservative care of this type is often successful for voluntary dislocations. Surgery was needed in order to repair the damage before the patient could return to sports.

Labral Tears of the Shoulder Are Not Age Dependent

Rotator cuff tears (RCTs) are more common as we get older. In this study, surgeons report on the relationship between RCTs, shoulder dislocations, and patient age. When the shoulder dislocates, the glenohumeral ligament is always torn. RCTs may or may not occur at the same time. This study shows that RCTs occur most often after repeated shoulder dislocations.

Patients at the Unit of Shoulder and Elbow Surgery in Ferrara, Italy were divided into three groups in this study. Each group had 50 patients. Group 1 had shoulder instability meaning the joint had dislocated at least twice. Group 2 had a complete RCT. Group 3 had both shoulder instability and RCTs. All patients were between the ages of 40 and 60 years old.

Arthroscopic exam found the following:

  • Group 1: Patients with instability had tears in the joint capsule and/or the labrum (a rim of cartilage around part of the shoulder socket).
  • Group 2: Findings matched the results of tests and imaging studies done before surgery; the supraspinatus tendon was torn most often (42 percent of cases). Patients often had tears in more than one tendon of the rotator cuff.
  • Group 3: One-third of the patients in this group had one or more torn tendons in the rotator cuff; one-third had just the torn capsule and labrum; one-third had both rotator cuff tear(s) and capsule and labral tears.

    The authors analyzed the data and made these observations:

  • A RCT is not linked with capsular or labral lesions; these injuries are independent of each other.
  • The more often the shoulder dislocates, the more likely a RCT will occur. The risk of RCT rises rapidly after seven dislocations.
  • It is impossible to tell if RCTs or capsule/labral tears cause or follow dislocation.
  • Labral tears do not depend on the person’s age or on the number of dislocations.

    The authors conclude age does not seem linked to labral or capsula tears. This is true despite the fact that there are a larger number of these injuries in patients 50 years old or older. RCTs are more common with recurrent shoulder dislocations.

  • Healing of Rotator Cuff Reruptures is Possible

    Rotator cuff tears of the shoulder can be repaired surgically. Some patients rerupture the repair. This report offers a long-term look at 20 patients with rerupture of the rotator cuff repaired the first time with an open incision. Short-term results for this same group were reported after 3.2 years. The results reported here were measured after 7.6 years.

    Clinical exam, X-rays, and MRI were used throughout follow-up with these patients. X-rays were used to show arthritic changes in the shoulder joint. MRIs showed the condition of the torn tendon(s). Motion, strength, and function were also measured.

    After the first three years, the patients with a rerupture still had better results than before surgery. After seven and a half years no one was any worse. Some patients were better than at the three-year check-up. Eight of the 20 showed healing had occurred. For those who still had a rupture, there was no change in the size of the tear.

    There were some changes seen between three and seven years. For example there were more arthritic changes in the shoulder joint. Some of the rotator cuff tendons had developed a lot of fatty streaks called fatty infiltration. The authors suspect further deterioration will occur with age.

    Results of this study show that small rotator cuff reruptures can heal over time. Changes can be seen in the tissue as much as three years later. Most of the time this new tissue had reduced strength.

    The authors say it’s better to have surgery to repair a rotator cuff even if it tears again compared to leaving a tear untreated. Patients seem to have better overall function despite the rerupture compared with an unrepaired rotator cuff tear.

    Review of Humeral Shaft Fractures with Radial Nerve Injury

    In this article surgeons from the Cleveland Clinic review humeral shaft (upper arm) fractures with radial nerve injuries. Anatomy of the upper arm and clinical exam of the fracture are described. Factors to be considered during treatment are also included.

    Humeral shaft fractures are named by their location and the amount of contact between the broken pieces. When the bone is broken in half it’s called a simple fracture. The break may be straight across (transverse) or at an angle (oblique). Other more complex breaks may result in a spiral fracture or pieces of bone called a comminuted fracture.

    Bone fragments can cut or damage the radial nerve as it travels down the arm. The risk of nerve injury is greatest along the lower third of the bone where the nerve is not separated from the bone by muscle. Radial nerve palsy after fracture may be partial or complete. Once the bone heals, the patient may or may not recover from the secondary nerve injury.

    If the fracture is closed (doesn’t break through the skin), then treatment without surgery is possible. This is true even if there’s nerve damage. In 70% of the closed fracture cases, the bone and nerve heal without surgery. If the patient shows signs of delayed nerve healing, then surgery later is an option.

    Surgery may also be needed for patients with severe trauma and fracture. The goal is to save nerve and blood supply to the arm. Pins to hold the bone in place may not be possible if the fracture is near the radial nerve. There is a danger of putting the pin through the nerve. A metal compression plate may work better. The condition of the nerve is investigated during the operation.

    The authors review various methods of nerve repair. The location of the injury and how long it’s been there are important factors. They suggest nerve grafting if there is a large defect in the nerve or great tension on the nerve. Nerve transfer or nerve reconstruction may be needed for more complex injuries.

    Rare But Dangerous Collar Bone Dislocation

    Although uncommon, posterior sternoclavicular joint (SCJ) dislocations are possible. A blow to the middle of the clavicle (collar bone) forces the bone inward. Dislocation occurs at the point where the clavicle attaches to the breast bone (sternum). The most common causes of this injury are car accidents (striking the steering wheel) and sports injuries. Less often, a shoulder injury is the indirect cause of a dislocated SCJ.

    In this article, three orthopedic surgeons from the Medical University of Ohio review this rare injury. The location of the esophagus, heart, lungs, and major blood vessels behind the sternum make this injury critical. The broken bone can pierce any of these structures. Because it can be fatal, successful management is important.

    The authors suggest knowing the anatomy of the SCJ is essential. A brief anatomy review of the SCJ, surrounding soft tissues, and structures underneath is presented. Signs and symptoms of compression of the various anatomical structures are also presented. Special imaging techniques with X-rays, CT scans, and ultrasound are given.

    The dislocation should be reduced (the joint is put back in place or relocated) in the first 48 hours. Three methods for closed (nonoperative) reduction are described. If it’s can’t be reduced without surgery, then advice and precautions are given for operative treatment.

    For example wires, screws, and pins must be used with extreme caution (if at all). They can come loose and move or migrate to the heart, aorta, or lung. Other ways to avoid complications from this injury are also discussed.

    Shoulder Fusion: When and How It’s Used

    In this article doctors from the Cleveland Clinic in Ohio review fusion of the shoulder joint called arthrodesis. With total shoulder replacements available today, the need for shoulder arthrodesis is much less. But there are still times when fusion is the only answer.

    The most common use of shoulder fusion is after severe shoulder injury from car accidents. Nerve damage or massive rotator cuff tears may leave the shoulder with severe loss of motion and function.

    Tumors that destroy tissue and bone is another problem that can lead to shoulder arthrodesis. Once the tumor and surrounding tissue have been removed, then the surgeon decides if shoulder replacement or shoulder fusion is best.

    Sometimes shoulder arthrodesis is needed after a total shoulder replacement (TSR). The TSR that fails for any reason may have to be removed. Loss of bone and muscle control may require a fusion to regain shoulder stability.

    The authors show how they used metal plating and screws to hold the shoulder in place. Some motion is still possible. The patient must be able to lift the arm to shoulder height and touch the top of the head. Available motion also allows the patient to reach into the back pocket on the same side as the fusion.

    Shoulder arthrodesis should not be used for patients with severe problems in both shoulders. Fusion in both shoulders wouldn’t allow them to do their daily activities of self-care. Older adults with neurologic problems are also not good candidates for this operation. Results are often unsatisfactory.

    Surgeons Give Thumbs Down to Treatment for Massive Rotator Cuff Tears

    There isn’t a good way to treat massive tears of the rotator cuff in the shoulder. In fact, some doctors label them “irreparable.” In this study, surgeons at the University of California – Los Angeles tried repairing 32 shoulders with massive, irreparable rotator cuff tears (RCTs) using an allograft reconstruction. They report it isn’t the treatment they’d hoped for.

    RCTs are described as “massive” if two or more of the four tendons are ruptured and a tendon repair fails. Allografting uses donated quadriceps, patellar, or Achilles tendons. The surgical method used to reconstruct the shoulder with the allograft is described.

    MRIs taken after the surgery showed complete failure in all cases. The grafted tissue was no longer attached to the bone. The head of the humerus had drifted or migrated upwards. Despite these results the patients reported improved pain and function. Only one patient had a graft rejection.

    The authors concluded allograft repair of massive RCTs doesn’t give better results than other methods of repair. Since it’s more expensive with a higher risk of graft rejection and infection, they don’t recommend using this method.

    Review of Total Shoulder Replacements

    Total shoulder replacement (TSR) has been around since the early 1950s. Improved implant design has made this a popular treatment for shoulder osteoarthritis. In this review article, doctors from Columbia University present the pros and cons of partial versus TSR. Types of implants and surgical techniques are also discussed.

    Replacing just one side of the shoulder joint is called a hemiarthroplasty. Usually the humeral head at the top of the upper arm is the half replaced. The other (socket) side is called the glenoid component. Studies show that 80 percent of patients who just have the humeral head replaced have good-to-excellent pain relief. They also report improved motion and strength.

    Hemiarthroplasty is advised for younger, more active patients. They usually have a better chance for a balanced joint. They can always convert to a TSR later. The downside of this approach is that the results of hemiarthroplasty are unpredictable. It seems that TSR gives better function. There are fewer complications or second operations needed with a TSR compared to the hemiarthroplasty.

    What does the future hold for shoulder replacements? The authors report new ideas for TSR are focused on getting rid of shoulder instability. There are too many problems right now with the glenoid implant coming loose. The search is on to find a more durable, biologic method of fixation. Implant design will continue to improve and allow for better matching to each patient’s anatomy.

    Results of Treatment for Isolated SLAP II Injury

    When patients aren’t happy with results of surgery, it’s a good idea to take a look back over cases and see what’s going on. In this study 41 athletes with a SLAP II lesion of the shoulder are treated with surgery. The goal was to repair the torn cartilage. Patients were followed for at least two years. The authors try to understand why patient satisfaction wasn’t higher.

    A type II SLAP injury means that the biceps tendon has pulled away from the bone and has taken a small piece of the cartilage with it. The cartilage called the labrum forms a rim around the shoulder. The labrum helps create a deeper socket for the shoulder. SLAP stands for superior-inferior labral anterior posterior lesion.

    This study is unique because only patients with isolated type II SLAP injuries were included. Many times there are other structures also damaged. The presence of other injuries makes it hard to tell what operation works best for the SLAP injury.

    The repair was done arthroscopically. A bioabsorbable device was used to anchor down the torn soft tissues. Bioabsorbable means it will dissolve over time without any other special treatment.

    One-third of the patients were unhappy with the results. More than half couldn’t go back to their preinjury level of sports. A few couldn’t play at all anymore. Night pain was a problem for many patients.

    The authors were confused because most patients tested well after the operation. Pain was less and activity level was better than before surgery. They posed two reasons for patient’s poor results.

    The first was high patient expectations and demands. The athletes wanted to return to their preinjury level of sports and couldn’t always do so. The second was operative technique. Patients who had a repair right through the rotator cuff had worse results. They had pain day and night.

    Labral tears in athletes are difficult to treat with good to excellent results. The results of this study help show that the surgeon should avoid inserting the arthroscope through the rotator cuff itself. More studies are needed to find an acceptable way to repair SLAP II injuries.

    Pain Location Does Not Help Identify Rotator Cuff Tears

    Some soft tissue lesions have very distinct pain patterns. When the patient points to a certain spot, the doctor knows what’s causing the problem. In this study doctors try to pinpoint pain patterns for rotator cuff tears (RCTs). They discovered that pain from RCTs is not location specific.

    In other words, the location of the pain does not match the location of the RCT. The authors then looked at specific strength tests used to assess for RCTs. They asked the question: How much weakness signals a RCT?

    Muscle strength is graded from one (weakest) to five (normal or strongest). Each of the four tendons of the rotator cuff has its own specific strength test. Muscle weakness less than grade three is a useful test for diagnosing RCTs.

    They also found that any amount of weakness in the supraspinatus test is abnormal. And the tests were not all equally accurate because some muscles help compensate for weakness in others.

    This was the first study to show that doctors can’t rely on the pain location to diagnose a RCT. Muscle testing is helpful but MRIs and arthroscopic exam are the most accurate.

    Changes in Shoulder Rotation for Elite Baseball Pitchers

    Do professional baseball players have greater motion in their pitching arm? . Throwing athletes often have shoulder overuse injuries. This study was done to compare shoulder motion and stiffness in the pitching arm compared to the nonthrowing shoulder. The researchers expected the stresses of long-term throwing to change shoulder motion.

    Thirty-four professional baseball pitchers joined the study. Range of motion (ROM) and stiffness were measured using two different methods. They found the pitching shoulder had more outward (external) rotation and less inward (internal rotation) when compared to the other side.

    Greater external rotation can be explained by the arc of motion needed for throwing. The pitcher begins in a position of extreme external rotation before releasing the ball forward. According to the results of this study, the total arc of rotation was unchanged. Total motion was the same from side to side but there was a shift in where the rotation occurred from one side to the other.

    The front of the shoulder was more lax than the back half. The soft tissues, ligaments, and joint capsule may stretch out in the front from the constant position of external rotation. Measuring stiffness of the shoulders showed no overall difference in passive stiffness from side to side. The authors say the results of this study show that overuse of the throwing arm doesn’t lead to an unstable joint.

    Ultrasound Used to Review Results of Shoulder Surgery

    Rotator cuff tears (RCTs) are treated on the basis of how serious the damage is. For example if less than half of the tendon is torn, then the surgeon cleans up the area, a procedure called debridement.

    Loose fragments of tendon tissue are removed. Ragged edges are smoothed. Part of the bone over the shoulder called the acromion is cut out. This part of the operation is called an acromioplasty. The acromioplasty takes pressure off the rotator cuff as it slides and glides under the bone.

    A group of patients who had debridement and an acromioplasty for partial-thickness RCTs were followed for at least five years. Ultrasound was used as a fast and cost-effective way to examine the shoulder. In fact both shoulders were viewed this way.

    The authors found that nine out of 26 patients had a full-thickness tear of the rotator cuff. Three of those nine patients actually had RCTs in both shoulders.
    They conclude the earlier debridement and acromioplasty didn’t protect these patients from further damage. Most of the affected patients did not need any further surgery. Since some patients had RCTs on both sides, it may be these problems are due to aging and degeneration. Earlier treatment may not have been a failure after all.

    Doctors Review Use of Anchors and Tacks

    Much has changed in the world of shoulder surgery in the last few years. More operations are being done with small incisions using an arthroscope to see inside the joint. Soft tissues cut or torn can be repaired and reattached to the bone using new suture anchors and tacks. In this review article, surgeons discuss problems with such fixation devices and how to prevent them.

    The authors say surgeons must be aware of possible pitfalls in the use of suture anchors or tacks. They must read the manufacturer’s directions. Knowing the anatomy can help guide the surgeon in using the right location for placement of the anchors and tacks. A backup plan is important in case the device fails.

    Problems can occur such as sutures blocking the blood supply or cutting through the bone. They can break or come loose. A loose or broken anchor or tack can move inside the joint causing pain and loss of motion. Treatment depends on the problem and patient’s symptoms. The device may have to be taken out or a different type of implant used.

    The authors offer surgeons many tips on what to do if the sutures break or the knots don’t slide properly. Other more serious problems such as infection, inflammation, and bone loss are discussed in detail.

    Shoulder Capsule Tears on First Dislocation

    Finding the cause of a shoulder that dislocated more than once can be a challenge for the orthopedic surgeon. In this study, doctors from Japan found that a complete tear of the joint capsule is one injury that can cause anterior (forward) shoulder dislocation.

    They reviewed over 300 cases of shoulder instability treated with surgery. Twelve of those patients had a complete capsular tear. Twelve out of 300 is a four percent prevalence. Each patient had two or more dislocations of the same shoulder. Major trauma such as a fall or sports injury was the cause of the first dislocation.

    The shoulder is kept in its socket by many soft tissue and structural features of the shoulder. There are several ligaments that hold the shoulder in place and make up the entire capsule. For this study a capsular tear was defined as a tear of the inferior glenohumeral ligament. The ligament may tear and pull away from the bone.

    All 12 patients had arthroscopic surgery to find and repair the problem. With a complete capsular tear the surgeon can see the subscapularis muscle underneath the ligament. During the repair the surgeon stitches the ligament back together until the muscle can no longer be seen. Results were good. Nine of the 12 patients were able to go back to sports. Only one patient had another dislocation.

    The authors conclude that a capsular tear can occur at the time of the first shoulder dislocation. The ligament doesn’t just stretch and bleed. It actually tears enough to leave a hole open in the capsule or even pull away from the bone. Sewing the tear back together seems to be enough to repair the problem.

    Review of the Shoulder: Evaluation and Diagnosis

    In this article doctors from The Johns Hopkins University review the complexities of the shoulder. Diagnosis can be very difficult since there are so many parts to the joint. Many tests show there’s a problem in the shoulder but not what the problem is.

    The authors present a step-by-step way for the physician to examine the shoulder. The importance of patient history and the way symptoms begin are pointed out. They go over the exam basics for a rotator cuff problem. They also review nerve or neurologic conditions and acromioclavicular (AC) joint problems.

    The AC joint is in front of the shoulder where the collarbone meets the acromion. The acromion is a bridge of bone coming from the back of the shoulder blade, curving over the top of the shoulder. They also compare symptoms and test results for rotator cuff problems with a stiff shoulder.

    Many patients have more than one problem causing shoulder pain, loss of motion, or weakness. Pain patterns and symptoms can be the same for various conditions. A thorough evaluation is needed to make the diagnosis and to plan treatment. This article helps physicians sort out causes of shoulder pathology.

    What’s New in Shoulder Surgery? Review of New Sutures

    When it comes to reattaching ligaments, tendons, or other soft tissues in the shoulder what works best? Absorbable sutures? Braided or unbraided? Screw-in tacks? Hooked or knotless anchors and tacks? In this report surgeons at The Johns Hopkins University review use of anchors and tacks for shoulder surgery.

    The choice of anchors and tacks depends on the type of surgery being done. The authors say surgeons must choose based on the biomechanics and biology of tissue healing. The rate of healing as the soft tissue knits itself back to the bone depends on these two factors.

    Results of animal studies show how healing rates vary depending on different devices used to reattach the soft tissues. It takes at least 12 weeks for a secure fixation of the soft tissue to bone. Surgery can fail if movement puts too much stress on the healing tissue.

    Researchers are studying animal models and cadavers to find out how much force can be put on a normal tendon before it pulls away from the bone. The second step in this process is to find out the load it takes to pull away repaired tendon at six weeks and then at 12 weeks. Such information will help the surgeon choose the right anchor or tack to repair each injury.

    Each type of implant used to reattach soft tissues in the shoulder is reviewed for the surgeon. Rates of healing are listed when known. It’s unclear how long some sutures stay in the shoulder before dissolving. It’s not clear how long the implants need to stay intact for the tissue to heal enough to resist stress. The authors point out there are still many unknowns.