Richard S. Boorman

Characterizing the Functional Improvement After Total Shoulder Arthroplasty for Osteoarthritis

Background: Both shoulder surgeons and patients who are considering total shoulder arthroplasty are interested in the anticipated improvement in shoulder comfort and function after the procedure. The purpose of the present study was to characterize shoulder-specific functional gains in relation to preoperative shoulder function and to present this information in a way that can be easily communicated to patients who are considering this surgery.Methods: We analyzed the preoperative and follow-up shoulder function in patients managed with total shoulder arthroplasty for the treatment of primary glenohumeral osteoarthritis. Functional self-assessments were available for 102 (80%) of 128 shoulders after thirty to sixty months of follow-up. Outcome was assessed with respect to the change in the number of shoulder functions that were performable, the change in shoulder function as a percentage of the preoperative functional deficit, and the change in the ability to perform specific shoulder functions.Results: The average number of shoulder functions that were performable improved from four of twelve preoperatively to nine of twelve postoperatively (p < 0.01). Function improved in ninety-six shoulders (94%). The number of functions that were performable at the time of follow-up was positively associated with preoperative shoulder function (p < 0.05): the better the preoperative function, the better the follow-up function. The improvement in function was greatest for shoulders with less preoperative function (p < 0.01). On the average, patients regained approximately two-thirds of the functions that had been absent preoperatively. Significant improvement was noted in eleven of the twelve shoulder functions that were examined (p < 0.01). The chance of regaining a function that had been absent before surgery was 73%, whereas the chance of losing a function that had been present before surgery was 6%. Older men tended to have greater functional improvement than younger men.Conclusion: Total shoulder arthroplasty for the treatment of primary glenohumeral osteoarthritis significantly improves shoulder function. Postoperative function is related to preoperative function. The improvement that was observed in this clinical series can be conveyed to patients most simply by stating that, after surgery, shoulders typically regained approximately two-thirds of the functions that had been absent preoperatively.

Preoperative Factors Associated with Improvements in Shoulder Function After Humeral Hemiarthroplasty

BACKGROUND The relationship between the characteristics of the shoulder that can be determined before humeral hemiarthroplasty and the functional improvement after surgery is not known. The goal of this study was to test the hypothesis that the functional outcome of this procedure correlated significantly with factors that are identifiable preoperatively. METHODS The study group included seventy-one shoulders in sixty-eight patients undergoing hemiarthroplasty, performed by the same surgeon, for diagnoses other than acute fracture. The mean age of the patients was sixty-one years (range, thirty to eighty-three years). The results were characterized in terms of the change in self-assessed shoulder function and general health status at an average of forty-nine months (range, twenty-four to 142 months) after surgery. RESULTS The preoperative absence of erosion of the glenoid was associated with greater improvement in shoulder function and level of comfort after hemiarthroplasty (p < 0.001). Shoulders that had not had previous surgery had greater functional improvement than did those that had previous surgery (p = 0.012). Shoulders with an intact rotator cuff showed significantly (p < 0.5) greater improvement in the ability to lift weight above shoulder level after hemiarthroplasty (p <0.5). With regard to diagnoses, shoulders with rheumatoid arthritis, capsulorrhaphy arthropathy, and cuff tear arthropathy had the least functional improvement, whereas those with osteonecrosis (p = 0.0004) and with primary (p = 0.02) and secondary degenerative joint disease (p = 0.03) had the greatest improvement. Patient age and gender did not significantly affect the outcome. CONCLUSIONS These results suggest that the functional improvement following humeral hemiarthroplasty is related to factors that are identifiable before surgery. These data may be of benefit in preoperative discussions with patients who have a shoulder disorder and are considering treatment with hemiarthroplasty.

A Randomized Clinical Trial Comparing Open and Arthroscopic Stabilization for Recurrent Traumatic Anterior Shoulder Instability Two-Year Follow-up with Disease-Specific Quality-of-Life Outcomes

BACKGROUND The literature comparing open and arthroscopic repair for glenohumeral instability is conflicting. We performed a prospective, expertise-based, randomized clinical trial to compare open shoulder stabilization with arthroscopic shoulder stabilization by measuring quality-of-life outcomes and recurrence rates at two years among patients treated for traumatic anterior shoulder instability. METHODS Computer-generated, variable-block-size, concealed randomization allocated 196 patients to either the open-repair group (n = 98) or the arthroscopic-repair group (n = 98). An expertise-based randomization design was employed to avoid a differential bias in terms of physician experience. Outcomes were measured at baseline, at three and six months postoperatively, and at one and two years postoperatively with use of the Western Ontario Shoulder Instability Index (WOSI) and the American Shoulder and Elbow Surgeons (ASES) functional outcome scale. Recurrent instability was also analyzed. RESULTS There were no significant differences in outcome scores at baseline. At two years, seventy-nine patients in the open group and eighty-three patients in the arthroscopic group were available for follow-up. There was no significant difference in mean WOSI scores between the groups; the mean WOSI score (and standard deviation) for the open group was 85.2 ± 20.4 (95% confidence interval [CI] = 80.5 to 89.8), and for the arthroscopic group, 81.9 ± 19.8 (95% CI = 77.4 to 86.4); p = 0.31. There was also no significant difference in mean ASES scores: 91.4 ± 12.7 (95% CI = 88.5 to 94.4) for the open group and 88.2 ± 15.9 (95% CI = 84.6 to 91.8) for the arthroscopic group; p = 0.17. Recurrence rates at two years were significantly different: 11% in the open group and 23% in the arthroscopic group (p = 0.05). Recurrent instability was more likely in patients with a preoperative Hill-Sachs lesion and in male patients who were twenty-five years old and younger. There was no significant difference in shoulder motion between the groups at two years. CONCLUSIONS There was no difference between open and arthroscopic repair in terms of patient quality of life. Open repair resulted in a significantly lower risk of recurrence. Secondary outcome data from this trial suggest that open surgical repair may be recommended to reduce the risk of recurrent instability in younger male patients with a Hill-Sachs lesion.

Changes in mechanical loading lead to tendonspecific alterations in MMP and TIMP expression: influence of stress deprivation and intermittent cyclic hydrostatic compression on rat supraspinatus and Achilles tendons.

Background Tendinopathy commonly occurs in tendons with large in vivo loading demands like the Achilles tendon (AT) and supraspinatus tendon (SST). In addition to differences in their local anatomic environment, these tendons are designed for different loading requirements because of the muscles to which they attach, with the AT experiencing higher loads than the SST. One possible factor in the progression of tendinopathy is the interplay between mechanical loading and the regulation of enzymes that degrade the extracellular matrix (matrix metalloproteinases (MMPs)) and their inhibitors (tissue inhibitor of metalloprotienases (TIMPs)). Thus, overuse injuries may have different biological consequences in tendons designed for different in vivo loading demands. Aim In this study, the tendon-specific regulation of MMP-13, MMP-3 and TIMP-2 expression in rat AT and SST exposed to two different mechanical environments was investigated. Methods Rat AT and SST were exposed to stress deprivation (ie, detached from attachments) and intermittent cyclic hydrostatic compression (with attachments intact). Levels of MMP-13, MMP-3 and TIMP-2 mRNA were evaluated in time-zero control, attached, stressdeprived and “compressed” tendons. Results Stress deprivation led to elevated expression of MMP-13, MMP-3 and TIMP-2 in both tendons, although the magnitude of the increase was greater for the SST than the AT. Intermittent cyclic hydrostatic compression of attached tendons increased expression of MMP-13 in the SST, but not the AT. Conclusions The results of this study suggest that stress deprivation may be one contributor to the progression of tendinopathy in AT and SST, where the tendon designed for the lower in vivo loading demand (SST) was the most affected by a change in mechanical loading. The unique upregulation of MMP-13 with hydrostatic compression supports the impingement injury theory for rotator cuff tears.

Glenoid cementing may generate sufficient heat to endanger the surrounding bone.

Glenoid loosening is a common complication of shoulder arthroplasty. One possible cause is bone necrosis from the exothermic reaction of polymethylmethacrylate. The relationship between the amount of cement used in glenoid fixation and the risk of thermal injury to bone was examined. Glenoid arthroplasty was done on 17 fresh cadaver scapulas, recording the amount of cement used. The bone surface temperature during cement curing was measured using infrared thermography. Using these data and published thresholds for thermal necrosis, the frontal plane area of bone that would be at risk for necrosis in vivo was estimated. The average weight of cement implanted was 5.35 g (2.65–8.08 g). The maximum temperature recorded averaged 64.7° C (48.2°–76.8° C). The area of bone at risk correlated with the amount of cement used. This study indicates that potentially dangerous amounts of heat may be generated during cementing of glenoid components.

Optimizing the Glenoid Contribution to the Stability of a Humeral Hemiarthroplasty without a Prosthetic Glenoid

BACKGROUND In a shoulder requiring arthroplasty, if the glenoid is flat or biconcave, the surgeon can restore the desired glenoid stability by using a glenoid prosthesis with a known surface geometry or by modifying the surface of the glenoid to a geometry that provides the desired glenoid stability. This study tested the hypotheses that (1) the stability provided by the glenoid is reduced by the removal of the articular cartilage; (2) the stability contributed by the glenoid is compromised by loss of its articular cartilage, and this lost stability can be restored by spherical reaming along the glenoid centerline; and (3) the stability of a reamed glenoid is comparable with that of a native glenoid and with that of a polyethylene glenoid with similar surface geometry; and (4) the glenoid stability can be predicted from the glenoid surface geometry. METHODS The stability provided by the glenoid in a given direction can be characterized by the maximal angle that the humeral joint reaction force can make with the glenoid centerline before the humeral head dislocates; this quantity is defined as the balance stability angle in the specified direction. The balance stability angles were both calculated and measured in eight different directions for an unused polyethylene glenoid component and eleven cadaveric glenoids in four different states: (1) native without the capsule or the rotator cuff, (2) denuded of cartilage and labrum, (3) after reaming the glenoid surface around the glenoid centerline with use of a spherical reamer with a radius of 25 mm, and (4) after reaming around the glenoid centerline with use of a spherical reamer with a radius of 22.5 mm. RESULTS The calculated and measured balance stability angles for each direction in each glenoid were strongly correlated. Denuding the glenoids of the articular cartilage reduced the glenoid contribution to stability, especially in the posterior direction. Reaming the glenoid restored the stability to values comparable with those of the normal glenoid. For example, the average calculated balance stability angle (and standard deviation) in the posterior direction for all eleven glenoids was 24 degrees for the native glenoids, 14 degrees for the denuded glenoids, 25 degrees for the glenoids reamed to a radius of 25 mm, and 33 degrees for the glenoids reamed to a radius of 22.5 mm. The values for the glenoids reamed to 25 mm (25 degrees ) were similar to those of a polyethylene glenoid of the same radius of curvature. For glenoids reamed to 22.5 mm, the average difference between the actual balance stability angle and that predicted from the glenoid geometry was 3.4 degrees +/- 2.4 degrees. CONCLUSIONS The glenoid contribution to shoulder stability was decreased by the removal of cartilage and labrum and was restored by spherical reaming to a level similar to resurfacing the glenoid with a polyethylene component.

Complications following arthroscopic fixation of acromioclavicular separations: a systematic review of the literature.

Purpose Over the past decade, a number of arthroscopic or arthroscopically assisted reconstruction techniques have emerged for the management of acromioclavicular (AC) separations. These techniques provide the advantage of superior visualization of the base of the coracoid, less soft tissue dissection, and smaller incisions. While these techniques have been reported to provide excellent functional results with minimal complications, discrepancies exist within the literature. This systematic review aims to assess the rate of complications following these procedures. Methods Two independent reviewers completed a search of Medline, Embase, PubMed, and the Cochrane Library entries up to December 2013. The terms “Acromioclavicular Joint (MeSH)” OR “acromioclavicular* (text)” OR “coracoclavicular* (text)” AND “Arthroscopy (MeSH)” OR “Arthroscop* (text)” were used. Pooled estimates and 95% confidence intervals were calculated assuming a random-effects model. Statistical heterogeneity was quantified using the I2 statistic. Level of evidence IV Results A total of 972 abstracts met the search criteria. After removal of duplicates and assessment of inclusion/exclusion criteria, 12 articles were selected for data extraction. The rate of superficial infection was 3.8% and residual shoulder/AC pain or hardware irritation occurred at a rate of 26.7%. The rate of coracoid/clavicle fracture was 5.3% and occurred most commonly with techniques utilizing bony tunnels. Loss of AC joint reduction occurred in 26.8% of patients. Conclusion Arthroscopic AC reconstruction techniques carry a distinct complication profile. The TightRope/Endobutton techniques, when performed acutely, provide good radiographic outcomes at the expense of hardware irritation. In contrast, graft reconstructions in patients with chronic AC separations demonstrated a high risk for loss of reduction. Fractures of the coracoid/clavicle remain a significant complication occurring predominately with techniques utilizing bony tunnels.

USING THE MODIFIED DELPHI METHOD TO ESTABLISH CLINICAL CONSENSUS FOR THE DIAGNOSIS AND TREATMENT OF PATIENTS WITH ROTATOR CUFF PATHOLOGY

BackgroundPatients presenting to the healthcare system with rotator cuff pathology do not always receive high quality care. High quality care occurs when a patient receives care that is accessible, appropriate, acceptable, effective, efficient, and safe. The aim of this study was twofold: 1) to develop a clinical pathway algorithm that sets forth a stepwise process for making decisions about the diagnosis and treatment of rotator cuff pathology presenting to primary, secondary, and tertiary healthcare settings; and 2) to establish clinical practice guidelines for the diagnosis and treatment of rotator cuff pathology to inform decision-making processes within the algorithm.MethodsA three-step modified Delphi method was used to establish consensus. Fourteen experts representing athletic therapy, physiotherapy, sport medicine, and orthopaedic surgery were invited to participate as the expert panel. In round 1, 123 best practice statements were distributed to the panel. Panel members were asked to mark “agree” or “disagree” beside each statement, and provide comments. The same voting method was again used for round 2. Round 3 consisted of a final face-to-face meeting.ResultsIn round 1, statements were grouped and reduced to 44 statements that met consensus. In round 2, five statements reached consensus. In round 3, ten statements reached consensus. Consensus was reached for 59 statements representing five domains: screening, diagnosis, physical examination, investigations, and treatment. The final face-to-face meeting was also used to develop clinical pathway algorithms (i.e., clinical care pathways) for three types of rotator cuff pathology: acute, chronic, and acute-on-chronic.ConclusionThis consensus guideline will help to standardize care, provide guidance on the diagnosis and treatment of rotator cuff pathology, and assist in clinical decision-making for all healthcare professionals.

New perspectives on bioengineering of joint tissues: joint adaptation creates a moving target for engineering replacement tissues.

The current paradigm in tissue engineering is that “full regeneration” or “total replacement” of normal tissue is required in order to restore joint function. However, there is considerable evidence that suggests that targets other than “normality” may actually be required for tissue substitutes. Sometimes “less than normal” tissue properties of substitutes may be required following an injury, and sometimes “more than normal” may be required (following tissue degradation, damage, and failure). Diarthrodial joints function as “organs” in a physiological sense and normal individual joint tissues work together to share the mechanical requirements demanded by internal and external forces. Each tissue has some genetic and biological ability to adapt and/or remodel, to accommodate to the changing biomechanical needs invoked by injury and each tissue changes with age. This dynamic genetic and environmentally driven situation affecting the (uninjured) tissues in both injured and uninjured joints suggests that there is a “moving target” for bioengineered replacement tissues. After degeneration, damage, and failure of adaptation of other joint components, the mechanical requirements of replacement tissues likely increases dramatically beyond those of their normal counterparts. These concepts have important implications to designs of tissue bioengineering experiments and to their mechanical targets.

Complexity of determining cause and effect in vivo after antisense gene therapy.

Injuries to joint tissues are major clinical problems occurring with significant frequency and resulting in the formation of scar tissue or in some tissues with no healing at all. Such scar tissue has compromised biomechanical integrity, which leads to impaired function, increased risk of reinjury, induction of remodeling in other joint tissues and increases the risk of diseases such as ostheoarthritis. Development of new therapies, such as gene therapy, to enhance repair could have a significant impact on quality of life for patients. The well-characterized rabbit medial collateral ligament injury model was used to transiently modulate the expression of specific molecules during early stages of healing. The small matrix proteoglycan decorin, known to influence matrix assembly and to bind and growth factors, was targeted in vivo using decorin-specific antisense oligodeoxynucleotides and Hemagglutinating Virus of Japan-Liposome method. After 4 weeks of healing, scar tissue was assessed after antisense exposure by reverse transcription polymerase chain reaction, Western Blot analysis, light and transmission electron microscopy, and biomechanically for low and high load behavior. Ligament scar messenger ribonucleic acid and protein levels for decorin decreased and collagen fibril diameter size increased after antisense treatment. Creep and stress at failure improved after antisense treatment indicating a functional improvement in the scar tissue. However, messenger ribonucleic acid levels for multiple genes were affected by the decorin-specific antisense treatment and therefore all of the observed improvements in the scar tissue cannot be directly ascribed to depressing decorin levels.