Throwing injuries: diagnosis and treatment

Acellular Cartilage Repair Technique Based on Ultrapurified Alginate Gel Implantation for Advanced Capitellar Osteochondritis Dissecans

Background:

One of the most important limitations of osteochondral autograft transplant is the adverse effect on donor sites in the knee. Ultrapurified alginate (UPAL) gel is a novel biomaterial that enhances hyaline-like cartilage repair for articular defects. To avoid the need for knee cartilage autografting when treating osteochondritis dissecans (OCD) of the capitellum, we developed a surgical procedure involving a bone marrow stimulation technique (BMST) augmented by implantation of UPAL gel.

Hypothesis:

BMST augmented by UPAL gel implantation improves the cartilage repair capacity and provides satisfactory clinical outcomes in OCD of the capitellum.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 5 athletes with advanced capitellar OCD in the dominant elbow underwent BMST augmented by implantation of UPAL gel. The osteochondral defects were filled with UPAL gel after BMST. At a mean follow-up of 97 weeks, all patients were evaluated clinically and radiographically.

Results:

At final follow-up, all 5 patients had returned to competitive-level sports, and 4 patients were free from elbow pain. The mean Timmerman-Andrews score significantly improved from 100 to 194 points. Radiographically, all patients exhibited graft incorporation and a normal contour of the subchondral cortex. Magnetic resonance imaging showed that the preoperative heterogeneity of the lesion had disappeared, and the signal intensity had returned to normal. Arthroscopic examinations consistently exhibited improvement in the International Cartilage Regeneration and Joint Preservation Society (ICRS) grade of lesions from 3 or 4 to 1 or 2 in 4 patients at 85 weeks postoperatively. Histologic analysis of biopsy specimens revealed an average total ICRS Visual Assessment Scale II histologic score of 1060.

Conclusion:

The acellular cartilage repair technique using UPAL gel for advanced capitellar OCD provided satisfactory clinical and radiographic results. The present results suggest that this novel technique is a useful, minimally invasive approach for treating cartilaginous lesions in athletes.

Predictors of Unsuccessful Nonoperative Management of Capitellar Osteochondritis Dissecans

BACKGROUND

Osteochondritis dissecans of the humeral capitellum (capitellar OCD) is a common injury among adolescent throwing athletes. Some younger patients with incomplete maturity of the epiphysis and early-stage capitellar OCD are good candidates for nonoperative treatment. However, during initial examination, predicting the need for surgical treatment in patients with capitellar OCD is difficult.

PURPOSE

To perform multivariate ordered logistic regression analysis of data obtained from patients' medical records and images on initial examination and identify the predictors of unsuccessful nonoperative management of capitellar OCD.

STUDY DESIGN

Cohort study (prognosis); Level of evidence, 2.

METHODS

This study included 245 elbows with capitellar OCD (all male; mean age, 14 years [range, 10-27 years]). Patients were divided into 3 groups comprising 148 elbows requiring an immediate operation on initial examination, 48 requiring nonsurgical treatment, and 49 requiring an operation after nonoperative management. Baseline data and radiographic parameters, such as lesion location, lesion size, modified Minami classification, radial head size, skeletal age difference between both elbows on initial examination, lesion size on computed tomography, and staging on magnetic resonance imaging, were retrospectively reviewed. Univariate and multivariate ordered logistic regression analyses of spontaneous healing of the lesion were conducted.

RESULTS

Univariate logistic regression analysis showed that radial head enlargement and skeletal age difference were significantly associated with spontaneous healing. In multivariate ordered logistic regression analysis, radial head enlargement (anteroposterior and lateral) and skeletal age difference were significant predictors of lack of spontaneous healing (odds ratio [OR], 2.76, P =.025; OR, 7.92, P =.026; and OR, 1.84, P =.0089, respectively).

CONCLUSION

To predict spontaneous healing in the moderate stage, plain radiographs would be important to evaluate radiocapitellar congruity and skeletal age. This study showed that preoperative radiographic findings of radial head enlargement and advanced skeletal age of the throwing side compared with that of the nonthrowing side were predictors of advanced-stage capitellar OCD. Despite several limitations, the statistical significance and correlations herein provide important information on preoperative surgical planning to surgeons.

Autologous Osteochondral Mosaicplasty for Centrally and Laterally Located, Advanced Capitellar Osteochondritis Dissecans in Teenage Athletes: Clinical Outcomes, Radiography, and Magnetic Resonance Imaging Findings

BACKGROUND

Autologous osteochondral mosaicplasty (ie, mosaicplasty) results in satisfactory clinical outcomes and reliable return to play for patients with large or unstable lesions due to osteochondritis dissecans (OCD) of the humeral capitellum. However, the association between the healing of the reconstructed cartilage and clinical outcomes remains unclear.

PURPOSE

To evaluate the efficacy of mosaicplasty in teenage athletes through use of clinical scores and imaging. The secondary purpose was to compare the clinical outcomes with images of centrally and laterally located lesions.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This study analyzed 22 elbows (all male patients; mean age, 13.5 ± 1.2 years) with capitellar OCD managed with mosaicplasty. Patients were divided into 2 groups according to the location of the lesions: central (10 patients) and lateral (12 patients). Evaluation was performed through use of the clinical rating system of Timmerman and Andrews, plain radiographs, and magnetic resonance imaging (MRI; the cartilage repair monitoring system of Roberts). The mean follow-up period was 27.5 months (range, 24-48 months).

RESULTS

Lateral lesions were significantly larger than central lesions (147.1 ± 51.9 mm² vs 95.5 ± 27.4 mm², P = .01). No other significant differences were found between central and lateral lesions. Timmerman and Andrews scores for both central and lateral lesions improved significantly from 125.0 ± 30.1 points and 138.3 ± 34.5 points preoperatively to 193.5 ± 11.3 points and 186.7 ± 18.1 points, respectively, at final follow-up ( P < .0001, P < .0001). Radiography identified complete graft incorporation in all cases and the absence of severe osteoarthritic changes or displaced osteochondral fragments. In the lateral group, the radial head ratio at final follow-up (1.83 ± 0.23) was significantly larger than the preoperative findings (1.75 ± 0.14, P = .049). The quality of joint surface reconstruction was found to be acceptable for central and lateral lesions on MRI evaluation.

CONCLUSION

Mosaicplasty resulted in satisfactory clinical outcomes and smooth cartilage surface integrity in teenage athletes with OCD on their return to competition-level sports activities irrespective of lesion location.

The Functional Arm Scale for Throwers (FAST)-Part I: The Design and Development of an Upper Extremity Region-Specific and Population-Specific Patient-Reported Outcome Scale for Throwing Athletes

BACKGROUND

Upper extremity (UE) region-specific, patient-reported outcome (PRO) scales assess injuries to the UE but do not account for the demands of overhead throwing athletes or measure patient-oriented domains of health-related quality of life (HRQOL).

PURPOSE

To develop the Functional Arm Scale for Throwers (FAST), a UE region-specific and population-specific PRO scale that assesses multiple domains of disablement in throwing athletes with UE injuries. In stage I, a beta version of the scale was developed for subsequent factor identification, final item reduction, and construct validity analysis during stage II.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Three-stage scale development was utilized: Stage I (item generation and initial item reduction) and stage II (factor analysis, final item reduction, and construct validity) are reported herein, and stage III (establishment of measurement properties [reliability and validity]) will be reported in a companion paper. In stage I, a beta version was developed, incorporating National Center for Medical Rehabilitation Research disablement domains and ensuring a blend of sport-related and non-sport-related items. An expert panel and focus group assessed importance and interpretability of each item. During stage II, the FAST was reduced, preserving variance characteristics and factor structure of the beta version and construct validity of the final FAST scale.

RESULTS

During stage I, a 54-item beta version and a separate 9-item pitcher module were developed. During stage II, a 22-item FAST and 9-item pitcher module were finalized. The factor solution for FAST scale items included pain (n = 6), throwing (n = 10), activities of daily living (n = 5), psychological impact (n = 4), and advancement (n = 3). The 6-item pain subscale crossed factors. The remaining subscales and pitcher module are distinctive, correlated, and internally consistent and may be interpreted individually or combined.

CONCLUSION

This article describes the development of the FAST, which assesses clinical outcomes and HRQOL of throwing athletes after UE injury. The FAST encompasses multiple domains of disability and demonstrates excellent construct validity.

CLINICAL RELEVANCE

The FAST provides a single UE region-specific and population-specific PRO scale for high-demand throwers to facilitate measurement of impact of UE injuries on HRQOL and clinical outcomes while quantifying recovery for comparative effectiveness studies.

Stress Distribution in Superior Labral Complex and Rotator Cuff During In Vivo Shoulder Motion: A Finite Element Analysis

PURPOSE

To quantitatively and qualitatively evaluate the impingement behavior between structures within the glenohumeral joint under simulated abduction-external rotation (ABER) motion using finite element analysis.

METHODS

Computed tomography (CT) scanning of 1 shoulder in a volunteer was performed at 0° and 120° of shoulder abduction with external rotation (ABER position), followed by magnetic resonance imaging at 0° of abduction. The CT and magnetic resonance images were then imported into a customized software program to undergo 3-dimensional reconstruction followed by finite element modeling of the bone and soft tissue including the upper part of the rotator cuff and glenohumeral labral complex. Glenohumeral motion from 0° to the ABER position was simulated by CT images in 2 different humeral positions. On the basis of simulated humeral motion with respect to the scapula, we measured the stress value on the biceps-labral complex and upper part of the rotator cuff as a consequence of their structural deformation. In addition, we intended to design 2 types of labra--a normal stable labrum and an unstable posterosuperior labrum--to evaluate the geometric alteration and resulting stress change on the posterosuperior labrum against a compressive force from the humeral head and rotator cuff.

RESULTS

In the ABER position, the posterosuperior labrum was deformed by the humeral head and interposed posterior part of the rotator cuff. When viewed from the rotator cuff, the posterior part of the rotator cuff came into contact with the posterosuperior labrum as external rotation increased. The measured peak contact stress values were 19.7 MPa and 23.5 MPa for the posterosuperior labrum and the upper rotator cuff, respectively. The stress values for both structures decreased to 5.8 MPa and 18.1 MPa, respectively, in the simulated SLAP model. The root of the long head of the biceps became compressed halfway through the range of motion by the humeral head, especially from the part involving horizontal extension and external rotation, resulting in a high stress of 22.4 MPa.

CONCLUSIONS

In this simulated SLAP model, the posterosuperior labrum was medially displaced by the humeral head and upper rotator cuff in the ABER position, causing a functional loss of the spacer effect.

CLINICAL RELEVANCE

In SLAP lesions, the posterosuperior labrum loses its ability to function as a spacer in certain positions (especially ABER) and may decrease the important spacer effect between the humerus and the rotator cuff; this may lead to posterosuperior subluxation of the humeral head or rotator cuff abnormalities and tears during repetitive ABER tasks.

Effect of posterior shoulder tightness on internal impingement in a cadaveric model of throwing

PURPOSE

Posterior shoulder tightness is common in throwing athletes, especially those with symptomatic shoulder internal impingement. The role of posteroinferior capsular contracture in the pathoetiologies of throwing-related injuries caused by shoulder internal impingement remains unclear. The purpose of this study was to assess effect of posterior shoulder tightness on internal impingement in a cadaveric model of throwing.

METHODS

Seven fresh-frozen cadaveric shoulders were tested with the shoulder abducted to 90° and at maximum external rotation to simulate the late cocking phase of throwing motion. Glenohumeral joint contact pressure and area through internal impingement, humeral head shift, and the maximum humeral rotation angle were measured. Posteroinferior capsular plication was performed to simulate posteroinferior capsular tightness and induce glenohumeral internal rotation deficit.

RESULTS

Following generation of simulated posteroinferior capsular tightness with resultant glenohumeral internal rotation deficit, glenohumeral contact pressure was significantly increased (P < 0.05), the impinged area of rotator cuff tendon was significantly decreased (P < 0.05), and the humeral head shifted posteriorly (P < 0.05) during shoulder internal impingement.

CONCLUSION

Excessive posteroinferior capsular tightness can cause forceful internal impingement of the shoulder at maximum external rotation position.

Magnetic Resonance Imaging Staging to Evaluate the Stability of Capitellar Osteochondritis Dissecans Lesions

BACKGROUND

Treatment for capitellar osteochondritis dissecans (COCD) lesions is usually based on their stability from the bony floor after arthroscopic or open direct observation. Thus, a noninvasive means of lesion stability assessment by use of imaging is desirable to preoperatively determine treatment strategy.

PURPOSE

To evaluate our modified MRI staging system for COCD, we compared the results of MRI staging with the International Cartilage Repair Society (ICRS) classification for lesion stability. Intra- and interrater reliability for MRI staging was examined as well.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Fifty-two COCD lesions were preoperatively evaluated by T2-weighted MRI and classified into 5 stages: stage 1 = normally shaped capitellum with several spotted areas of high signal intensity that is lower than that of cartilage; stage 2 = as with stage 1 but with several spotted areas of higher intensity than that of cartilage; stage 3 = as with stage 2 but with both discontinuity and noncircularity of the chondral surface signal of the capitellum and no high signal interface apparent between the lesion and the floor; stage 4 = lesion separated by a high intensity line in comparison with cartilage; and stage 5 = capitellar lesion displaced from the floor or defect of the capitellar lesion noted. The MRI staging results were compared with the intraoperative ICRS classification for lesion stability of each patient. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were all determined for fragment instability. Intra- and interrater correlations for our MRI staging were calculated among 3 examiners.

RESULTS

Preoperative MRI grading correctly matched ICRS classification in 49 of 52 patients (94%), with a sensitivity of 100% and a specificity of 80%. The PPV and NPV were 93% and 100%, respectively, for diagnosing lesion instability. Intrarater reliability (intraclass correlation coefficient [ICC]) for MRI staging was high at ICC(1, 1) = 0.86 and ICC(1, 2) = 0.90, as was interrater reliability at ICC(2, 1) = 0.82 and ICC(2, 3) = 0.88.

CONCLUSION

The MRI staging system provides accurate and reliable evidence for estimating ICRS classification and instability of COCD and is useful to decide appropriate treatment.

Posterosuperior and anterosuperior impingement of the shoulder in overhead athletes-evolving concepts

During throwing motion the athlete puts enormous stress on both the dynamic and the static stabilisers of the shoulder. Repetitive forces cause adaptive soft tissue and bone changes that initially improve performance but ultimately may lead to shoulder pathologies. Although a broad range of theories have been suggested for the pathophysiology of internal impingement, the reasons are obviously multifactorial. This review aims to critically analyse the current literature and to summarise clinically important information. The cardinal lesions of internal impingement, articular-sided rotator cuff tears and posterosuperior labral lesions, have been shown to occur in association with a number of other findings, most importantly glenohumeral internal rotation deficit and SICK scapula syndrome, but also with posterior humeral head lesions, posterior glenoid bony injury and, rarely, with Bankart and inferior glenohumeral ligament lesions. Extensive biomechanical and clinical research is necessary before a complete understanding and reconciliation of the varying theories of the pathomechanisms of injury can be developed.

Effect of rotator cuff muscle imbalance on forceful internal impingement and peel-back of the superior labrum: a cadaveric study

BACKGROUND

Throwing athletes with shoulder pain have been shown to have decreased rotator cuff muscle strength. Shoulder internal impingement and labral peel-back mechanism, as may occur during the late cocking phase of throwing motion, are thought to cause rotator cuff injury and type II superior labrum anterior and posterior lesions. Therefore, the objective of this study was to assess the effect of rotator cuff muscle force on internal impingement and the peel-back of the superior labrum by quantifying maximum external rotation, glenohumeral contact pressure, and position of the cuff insertion relative to the glenoid.

HYPOTHESIS

A change in rotator cuff muscle force will lead to increased external rotation, glenohumeral contact pressure, and overlap of the cuff insertion relative to the glenoid.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight fresh-frozen cadaveric shoulders were tested at the simulated late cocking position. Glenohumeral contact pressure, location of the cuff insertion relative to the glenoid, and maximum humeral external rotation angle were measured. The forces of the supraspinatus, subscapularis, and infraspinatus muscles were determined based on published clinical electromyographic data. To assess the effect of cuff muscle imbalance, each muscle force was varied. Horizontal abduction positions of 20 degrees , 30 degrees , and 40 degrees with respect to the scapular plane were tested.

RESULTS

Decreased subscapularis strength resulted in a significant increase in maximum external rotation (P <.001) and increased glenohumeral contact pressure (P <.01). The cuff insertion overlapped the edge of the glenoid at 30 degrees and 40 degrees of horizontal abduction for all muscle loading conditions.

CONCLUSION

Decreased subscapularis muscle strength in the position simulating the late cocking phase of throwing motion results in increased maximum external rotation and also increased glenohumeral contact pressure.

CLINICAL RELEVANCE

Athletes with decreased subscapularis muscle strength, such as fatigue with repetitive throwing, may be more susceptible to rotator cuff tears and type II superior labrum anterior and posterior lesions. Subscapularis muscle strengthening exercises may be beneficial for preventing these injuries.