Geriatric proximal humerus fracture operative management: a Truven Health Analytics database study (2015-2020)

BACKGROUND

The purpose of this study is to assess the trends in operative management of geriatric (≥65 years) proximal humerus fractures during a 6-year period (2015-2020) within an insurance claims database.

METHODS

This retrospective database cohort study used data gathered from the 2015-2020 IBM Truven MarketScan Commercial and IBM Truven MarketScan Medicare Supplemental databases. The International Statistical Classification of Disease and Related Health Problems, Tenth Revision, data was correlated to the Current Procedural Terminology code for shoulder arthroplasty (proximal humeral prosthetic replacement: 23616, shoulder hemiarthroplasty [HA]: 23470, reverse total shoulder arthroplasty [rTSA]: 23472) or open reduction internal fixation (ORIF; open treatment of proximal humerus fracture with internal fixation: 23615, open treatment of proximal humerus fracture-dislocation with internal fixation: 23680). We investigated the number of proximal humerus fracture operative cases per year, percentage arthroplasty used per year, rTSA and HA per year, hospital cost information, as well as percentage arthroplasty per US geographic region.

RESULTS

A total of 8057 operative proximal humerus fractures cases were identified in 7697 patients aged >65 years, with 0.45% (360 of 8057) being bilateral. There was a 40.8% decrease in the rate of operative management of proximal humerus fractures between the first half (2015-2017, 1687.3 ± 146.6) and the second half of the study period (2018-2020, 998.3 ± 258.7). Arthroplasty accounted for 78.7% of all surgeries, 91% of those being rTSA. The total number of cases of rTSA and ORIF performed decreased per year (P = .01). The downward trend of percentage ORIF per year approached significance (P = .054). Arthroplasty was a more expensive option of payment for total case by almost $850.00 (P = .001). There was a larger percentage of arthroplasty performed in the Northeast and North Central US geographic regions.

CONCLUSION

Despite the rise of both the elderly population and related geriatric proximal humerus fractures, they were less operatively represented in this insurance claims database across the 6-year period. There may be a trend to use less ORIF when addressing these fractures. Although it incurred a higher in-hospital cost, arthroplasty was being performed at a higher percentage in the Northeast and North Central regions of the United States.

Factors Associated With Humeral Avulsion of Glenohumeral Ligament Lesions in Patients With Anterior Shoulder Instability: An Analysis of the MOON Shoulder Instability Cohort

Background

Humeral avulsion of the glenohumeral ligament (HAGL) lesions are an uncommon cause of anterior glenohumeral instability and may occur in isolation or combination with other pathologies. As HAGL lesions are difficult to detect via magnetic resonance imaging (MRI) and arthroscopy, they can remain unrecognized and result in continued glenohumeral instability.

Purpose

To compare patients with anterior shoulder instability from a large multicenter cohort with and without a diagnosis of a HAGL lesion and identify preoperative physical examination findings, patient-reported outcomes, imaging findings, and surgical management trends associated with HAGL lesions.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Patients with anterior glenohumeral instability who underwent surgical management between 2012 and 2020 at 11 orthopaedic centers were enrolled. Patients with HAGL lesions identified intraoperatively were compared with patients without HAGL lesions. Preoperative characteristics, physical examinations, imaging findings, intraoperative findings, and surgical procedures were collected. The Student t test, Kruskal-Wallis H test, Fisher exact test, and chi-square test were used to compare groups.

Results

A total of 21 HAGL lesions were identified in 915 (2.3%) patients; approximately one-third (28.6%) of all lesions were visualized intraoperatively but not identified on preoperative MRI. Baseline characteristics did not differ between study cohorts. Compared with non-HAGL patients, HAGL patients were less likely to have a Hill-Sachs lesion (54.7% vs 28.6%; P = .03) or an anterior labral tear (87.2% vs 66.7%; P = .01) on preoperative MRI and demonstrated increased external rotation when their affected arm was positioned at 90° of abduction (85° vs 90°; P = .03). Additionally, HAGL lesions were independently associated with an increased risk of undergoing an open stabilization surgery (odds ratio, 74.6 [95% CI, 25.2-221.1]; P < .001).

Conclusion

Approximately one-third of HAGL lesions were missed on preoperative MRI. HAGL patients were less likely to exhibit preoperative imaging findings associated with anterior shoulder instability, such as Hill-Sachs lesions or anterior labral pathology. These patients underwent open procedures more frequently than patients without HAGL lesions.

Performance of the PROMIS in Patients Undergoing 3 Common Elbow Procedures

Background:

Ulnar collateral ligament (UCL) reconstruction, distal biceps tendon repair, and elbow arthroscopic surgery are common elbow procedures performed in active patients.

Hypothesis:

We hypothesized (1) good to excellent correlation between Patient-Reported Outcomes Measurement Information System (PROMIS) instruments and traditional orthopaedic upper extremity patient-reported outcome (PRO) measures; (2) that PROMIS instruments would demonstrate ceiling effects; and (3) that the PROMIS physical function computer adaptive test (PF CAT) would demonstrate a low question burden compared with other PRO instruments.

Study Design:

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

Methods:

A total of 76 patients undergoing UCL repair/reconstruction, distal biceps tendon repair, or elbow arthroscopic surgery filled out the Short Form–36 Health Survey (SF-36) Physical Function subscale, EuroQol–5 Dimensions (EQ-5D) questionnaire, PROMIS PF CAT, and PROMIS upper extremity item bank (UE). Excellent correlation between PROs was defined as ≥.70.

Results:

The PROMIS PF CAT had excellent correlation with the SF-36 (r = 0.74; P < .0001), Disabilities of the Arm, Shoulder and Hand (DASH) survey (r = –0.76; P < .0001), and PROMIS UE (r = 0.73; P < .0001). The PROMIS UE demonstrated excellent correlation with the SF-36 (r = 0.73; P < .0001) and DASH survey (r = –0.81; P < .0001). The PROMIS UE had ceiling effects in 33% of patients. The SF-36 showed ceiling effects in 20% of patients. On average, patients answered 5.1 ± 2.2 questions on the PROMIS PF CAT.

Conclusion:

The PROMIS PF CAT and PROMIS UE are valid in patients undergoing distal biceps tendon repair, elbow arthroscopic surgery, and UCL repair. The PROMIS UE demonstrated high ceiling effects in younger, higher functioning patients and should be used with caution in this group. A further evaluation and modification of the PROMIS UE in younger, high-functioning patients are warranted. Finally, the PROMIS PF CAT exhibited a low question burden relative to traditional PRO instruments without the loss of reliability.

Performance of the PROMIS After Operative Interventions for Shoulder Instability

Background:

The Patient-Reported Outcomes Measurement Information System (PROMIS) was developed to capture patient-reported outcomes (PROs) in an efficient manner. Few studies have assessed this instrument postoperatively.

Purpose:

To compare the PROMIS Physical Function computer adaptive test (PROMIS PF CAT) and Upper Extremity (PROMIS UE) item bank to other previously validated PRO instruments and to evaluate ceiling and floor effects and construct validity responsiveness in patients who underwent operative interventions for shoulder instability.

Study Design:

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

Methods:

A total of 72 patients who underwent operative interventions for shoulder instability completed the American Shoulder and Elbow Surgeons (ASES) assessment form, Marx shoulder activity scale (Marx), 36-Item Short Form Health Survey physical function (SF-36 PF) and general health (SF-36 GH), Western Ontario Shoulder Instability Index (WOSI), PROMIS PF CAT, and PROMIS UE before surgery and then at 6 weeks and 6 months postoperatively. Correlation coefficients were calculated among these tools. The effect size of change was also calculated for each tool at each time point. A total of 91 patients who had also undergone surgery for shoulder instability completed these PRO instruments 2 years postoperatively. The percentage of patients hitting the ceiling and floor effects of each of the PRO instruments was calculated at all time points.

Results:

The PROMIS PF CAT demonstrated excellent-good correlation with the SF-36 PF at all postoperative time points (0.61 at 6 weeks, 0.68 at 6 months, and 0.64 at 2 years; P < .01 for all). The PROMIS UE showed excellent correlation with the ASES at 6 weeks postoperatively (0.73, P < .01). Both the PROMIS PF CAT and PROMIS UE demonstrated the ability to detect change after surgical interventions with a medium to large effect size. The PROMIS UE demonstrated a ceiling effect at 6 months (68.1%) and 2 years (67.0%) postoperatively. The PROMIS PF CAT demonstrated no ceiling effect at any time point.

Conclusion:

The PROMIS PF CAT demonstrated good to excellent correlation with other previously validated PRO instruments that assess physical function in patients with shoulder instability postoperatively. The PROMIS UE demonstrated good correlation with other PRO tools but had a significant ceiling effect and is not recommended for this patient population. Both tools demonstrated an ability to detect change after surgical interventions with a good effect size.

Intra-Articular Pathology Associated with Acute and Chronic Anterior Cruciate Ligament Reconstruction

BACKGROUND

Concomitant meniscal and chondral pathology is common at the time of anterior cruciate ligament reconstruction (ACL-R). The purpose of the present study was to report the prevalence of concomitant intra-articular pathology for patients undergoing acute or chronic anterior cruciate ligament reconstruction.

METHODS

This study represents a prospective, consecutively collected cohort of 255 patients undergoing both primary and revision ACL-R between January 2012 and December 2014 at a single institution. The cohort was divided into an acute surgical group, defined as surgery within six weeks of injury, and a chronic surgical group, greater than six weeks removed from injury. The median time from injury to surgery for the entire cohort was 37 days (range: 4 days to 855 days). Variables of interest included patient demographic characteristics, concomitant meniscal and chondral pathology, and meniscus treatment.

RESULTS

Patients treated in the chronic setting were slightly older (28.7 ± 11.6 years vs. 23.1 ± 8.6 years, P=0.001), had a higher prevalence of complex tears of the medial meniscus (37.2% vs. 7.7%, P=0.012) and cartilage injury (16.5% vs. 7.8%, P=0.03). After excluding revision ACL-R procedures, complex medial meniscus tears in chronic ACL-R were higher than in acute ACL-R (medial= 27.3% vs. 3.0%, P=0.022), however when age was considered, these tears were no longer more frequent than in the acute setting (P=0.056). Similarly, the prevalence of cartilage injury was equivalent between groups after correcting for age (P=0.167). Among primary ACL-R, there were more medial meniscus repairs in the acute surgical group compared to the chronic group (60.6% vs. 24.2%, P=0.003). After excluding complex tears, medial meniscus repair rates were no longer performed more frequently in patients undergoing acute ACL-R (59.4% vs. 33.3%, P=0.054).

CONCLUSIONS

Data from this prospective cohort suggest that with increasing time from ACL injury to ACL-R, medial meniscus pathology increases, with a lower likelihood of meniscal repair in all patients undergoing ACL-R. However, this finding is no longer statistically significant when considering only patients undergoing primary ACL-R. Age appears to play an important role in whether concomitant pathology develops following ACL rupture. Given these findings, early intervention may increase the ability to repair medial meniscus tears in the setting of ACL-R, but this conclusion is less supported in primary ACL-R.Level of Evidence: II.

Performance of the PROMIS in Patients After Anterior Cruciate Ligament Reconstruction

Background

The Patient-Reported Outcomes Measurement Information System (PROMIS) is designed to advance patient-reported outcome (PRO) instruments by utilizing question banks for major health domains.

Purpose

To compare the responsiveness and construct validity of the PROMIS physical function computer adaptive test (PF CAT) with current PRO instruments for patients before and up to 2 years after anterior cruciate ligament (ACL) reconstruction.

Study Design

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

Methods

Initially, 157 patients completed the PROMIS PF CAT, Short Form-36 Health Survey (SF-36 physical function [PF] and general health [GH]), Marx Activity Rating Scale (MARS), Knee injury and Osteoarthritis Outcome Score (KOOS activities of daily living [ADL], sport, and quality of life [QOL]), and EuroQol-5 dimensions questionnaire (EQ-5D) at 6 weeks, 6 months, and 2 years after ACL reconstruction. Correlations between instruments, ceiling and floor effects, effect sizes (Cohen d), and standardized response means to describe responsiveness were evaluated. Subgroup analyses compared participants with and without additional arthroscopic procedures using linear mixed models.

Results

At baseline, 6 weeks, and 6 months, the PROMIS PF CAT showed excellent or excellent-good correlations with the SF-36 PF (r = 0.75-0.80, P < .01), KOOS-ADL (r = 0.63-0.70, P < .01), and KOOS-sport (r = 0.32-0.69, P < .01); excellent-good correlation with the EQ-5D (r = 0.60-0.71, P < .01); and good correlation with the KOOS-QOL (r = 0.52-0.58, P < .01). As expected, there were poor correlations with the MARS (r = 0.00-0.24, P < .01) and SF-36 GH (r = 0.16-0.34, P < .01 ). At 2 years, the PROMIS PF CAT showed good to excellent correlations with all PRO instruments (r = 0.42-0.72, P < .01), including the MARS (r = 0.42, P < .01), indicating frequent return to preinjury function. The PROMIS PF CAT had the fewest ceiling or floor effects of all instruments tested, and patients answered, on average, 4 questions. There was no significant difference in baseline physical function scores between subgroups; at follow-up, all groups showed improvements in scores that were not statistically different.

Conclusion

The PROMIS PF CAT is a valid tool to assess outcomes after ACL reconstruction up to 2 years after surgery, demonstrating the highest responsiveness to change with the fewest ceiling and floor effects and a low time burden among all instruments tested. The PROMIS PF CAT is a beneficial alternative for assessing physical function in adults before and after ACL reconstruction.

Outside-In vs. Anteromedial Portal Drilling During Primary ACL Reconstruction: Comparison at Two Years

BACKGROUND

Anteromedial (AM) and outside-in (OI) are two commonly used techniques for drilling the femoral tunnel during anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to compare clinical and radiographic outcomes of patients undergoing primary ACLR using either AM or OI femoral drilling with minimum two year follow-up.

METHODS

Overall, 138 prospectively enrolled patients undergoing primary ACLR underwent AM or OI femoral drilling. Patients were categorized by femoral drilling technique and were evaluated pre-operatively as well as at six weeks and two years post-operatively. Outcomes scores were collected at each visit using SF-36 PCS and MCS components, KOOS, and the Knee Activity Rating Scale. Complications, including graft failure, stiffness requiring manipulation under anesthesia, and revision surgery were also collected.

RESULTS

Overall, 47 (34.1%) patients underwent AM femoral drilling and 91 (65.9%) patients underwent OI femoral drilling. Univariate analysis revealed no difference in pre-operative outcomes with the exception of the AM group having higher KOOS Knee Pain (p=0.023) and WOMAC Pain (p=0.036) scores. Postoperatively, OI femoral tunnels had a higher radiographic coronal angle (68.8°±8.6° vs 51.4°±11.3°; p<0.001) and knee extension (1.2°±2.7 vs 2.9°±4.0°; p=0.010). There were no differences in knee flexion, complications, or graft failure. Postoperatively, the AM group had higher KOOS ADL and WOMAC Functional (85 vs. 79 ,p=0.030) scores at the six week mark, although these differences did not meet the minimal clinically importance difference1. Graft failure at two years were similar in the AM and OI groups (8.5% vs. 6.6%, p=0.735). Multivariate analysis showed no clinical outcome differences between AM and OI techniques.

CONCLUSIONS

ACL reconstruction using the AM technique yielded lower radiographic coronal tunnel angle and slightly decreased knee extension. The theoretical risk of graft failure secondary to higher coronal angle of the graft as it passes around a sharper femoral tunnel aperture was not observed. Additionally, differences in pre-operative KOOS Knee pain existed but these differences were not significant postoperatively. We conclude no clinically relevant differences by two years in patients undergoing primary ACL reconstruction using either AM or OI femoral drilling techniques. Level of Evidence: Level II Prospective Comparative Study.

Intra- and interobserver agreement in the classification and treatment of distal third clavicle fractures

BACKGROUND

In treatment of distal third clavicle fractures, the Neer classification system, based on the location of the fracture in relation to the coracoclavicular ligaments, has traditionally been used to determine fracture pattern stability.

PURPOSE

To determine the intra- and interobserver reliability in the classification of distal third clavicle fractures via standard plain radiographs and the intra- and interobserver agreement in the preferred treatment of these fractures.

STUDY DESIGN

Cohort study (Diagnosis); Level of evidence, 3.

METHODS

Thirty radiographs of distal clavicle fractures were randomly selected from patients treated for distal clavicle fractures between 2006 and 2011. The radiographs were distributed to 22 shoulder/sports medicine fellowship-trained orthopaedic surgeons. Fourteen surgeons responded and took part in the study. The evaluators were asked to measure the size of the distal fragment, classify the fracture pattern as stable or unstable, assign the Neer classification, and recommend operative versus nonoperative treatment. The radiographs were reordered and redistributed 3 months later. Inter- and intrarater agreement was determined for the distal fragment size, stability of the fracture, Neer classification, and decision to operate. Single variable logistic regression was performed to determine what factors could most accurately predict the decision for surgery.

RESULTS

Interrater agreement was fair for distal fragment size, moderate for stability, fair for Neer classification, slight for type IIB and III fractures, and moderate for treatment approach. Intrarater agreement was moderate for distal fragment size categories (κ = 0.50, P < .001) and Neer classification (κ = 0.42, P < .001) and substantial for stable fracture (κ = 0.65, P < .001) and decision to operate (κ = 0.65, P < .001). Fracture stability was the best predictor of treatment, with 89% accuracy (P < .001).

CONCLUSION

Fracture stability determination and the decision to operate had the highest interobserver agreement. Fracture stability was the key determinant of treatment, rather than the Neer classification system or the size of the distal fragment.

Report from the 2013 AOA North American Traveling Fellowship

Focused on young surgeons starting their careers in academic orthopaedics, the John J. Fahey, MD, Memorial North American Traveling Fellowship (NATF) has served to promote clinical, intellectual, and scientific exchange in orthopaedic surgery for the last forty-five years. The 2013 NATF was a tremendous experience for each and every one of us. We quickly developed very tight bonds with each other and friendships that will undoubtedly last throughout our careers and lives. At each site on the fellowship tour, we were made to feel special by our hosts and everyone with whom we came into contact. We each feel that we achieved the goals set out by the AOA (American Orthopaedic Association), making the most of this phenomenal experience through academic exchange, socialization, and networking and developing an appreciation of the various paths to success in orthopaedic surgery.

The effect of matrix metalloproteinase inhibition on tendon-to-bone healing in a rotator cuff repair model

HYPOTHESIS

Recent studies have demonstrated a potentially critical role of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in the pathophysiology of rotator cuff tears. We hypothesize that local delivery of a MMP inhibitor after surgical repair of the rotator cuff will improve healing at the tendon-to-bone surface interface.

MATERIALS AND METHODS

Sixty-two male Sprague-Dawley rats underwent acute supraspinatus detachment and repair. In the control group (n=31), the supraspinatus was repaired to its anatomic footprint. In the experimental group (n=31), recombinant alpha-2-macroglobulin (A2M) protein, a universal MMP inhibitor, was applied at the tendon-bone interface with an identical surgical repair. Animals were sacrificed at 2 and 4 weeks for histomorphometry, immunohistochemistry, and biomechanical testing. Statistical comparisons were performed using unpaired t tests. Significance was set at P < .05.

RESULTS

Significantly greater fibrocartilage was seen at the healing enthesis in the A2M-treated specimens compared with controls at 2 weeks (P < .05). Significantly greater collagen organization was observed in the A2M-treated animals compared with controls at 4 weeks (P < .01). A significant reduction in collagen degradation was observed at both 2 and 4 weeks in the experimental group (P < .05). Biomechanical testing revealed no significant differences in stiffness or ultimate load-to-failure.

CONCLUSION

Local delivery of an MMP inhibitor is associated with distinct histologic differences at the tendon-to-bone interface after rotator cuff repair. Modulation of MMP activity after rotator cuff repair may offer a novel biologic pathway to augment tendon-to-bone healing after rotator cuff repair.

Assessment of vascularity of the femoral head using gadolinium (Gd-DTPA)-enhanced magnetic resonance imaging

In spite of extensive accounts describing the blood supply to the femoral head, the prediction of avascular necrosis is elusive. Current opinion emphasises the contributions of the superior retinacular artery but may not explain the clinical outcome in many situations, including intramedullary nailing of the femur and resurfacing of the hip. We considered that significant additional contribution to the vascularity of the femoral head may exist. A total of 14 fresh-frozen hips were dissected and the medial circumflex femoral artery was cannulated in the femoral triangle. On the test side, this vessel was ligated, with the femoral head receiving its blood supply from the inferior vincular artery alone. Gadolinium contrast-enhanced MRI was then performed simultaneously on both control and test specimens. Polyurethane was injected, and gross dissection of the specimens was performed to confirm the extraosseous anatomy and the injection of contrast. The inferior vincular artery was found in every specimen and had a significant contribution to the vascularity of the femoral head. The head was divided into four quadrants: medial (0), superior (1), lateral (2) and inferior (3). In our study specimens the inferior vincular artery contributed a mean of 56% (25% to 90%) of blood flow in quadrant 0, 34% (14% to 80%) of quadrant 1, 37% (18% to 48%) of quadrant 2 and 68% (20% to 98%) in quadrant 3. Extensive intra-osseous anastomoses existed between the superior retinacular arteries, the inferior vincular artery and the subfoveal plexus.

Open reduction and internal fixation of tibial pilon fractures using a lateral approach

OBJECTIVES

To assess the wound complications and reductions achieved in a cohort of patients with pilon fractures who were treated using a novel lateral approach.

DESIGN

Retrospective review.

SETTING

Two level 1 trauma centers affiliated with academic institutions.

PATIENTS/METHODS

All 44 fractures (in 43 patients) treated by the senior authors with open reduction and internal fixation (ORIF) using the lateral approach as the primary approach were included.

INTERVENTION

Data regarding medical comorbidities, mechanism of injury, soft-tissue injury sustained during the injury, treatment, wound healing, and secondary surgeries were recorded. Fractures were classified using the AO/OTA system with most being type C3. Eighteen fractures were open injuries (10 type 3). Fracture reductions were scored using the criteria of Teeny and Wiss.

MAIN OUTCOME MEASUREMENTS

Quality of articular reduction and soft-tissue healing.

RESULTS

An anatomic or good fracture reduction was achieved in 41 fractures (93%), and a fair reduction was obtained in 3 fractures. Two patients were successfully treated for deep infection (4.5%), and 2 patients developed a wound dehiscence (4.5%). There were no amputations. Twelve patients underwent secondary surgeries (27%). Five of these were for symptomatic screw removal (related to the fibular hardware in all cases), and the sixth was for planned removal of a syndesmotic-type screw (13.6%). Four were for nonunion, representing 9% of all cases. The remaining secondary surgeries (2 cases) were performed for infection. Overall, 13.6% of patients underwent a secondary surgical procedure to address nonunion or infection.

CONCLUSIONS

When applied in a staged fashion, the lateral surgical approach for pilon fractures provides excellent protection of the soft-tissue envelopes by creating thick flaps while allowing excellent visualization for reconstruction of the anterior and lateral distal tibia.

Direct injection of blood into the labrum enhances the stability provided by the glenoid labral socket

We tested the hypothesis that the stabilizing function of the labrum can be enhanced by inflating it with blood. In 6 fresh cadaveric glenoids, the anteroinferior stability provided by the glenoid was quantitated by measuring the maximal angle between the glenoid centerline and the direction of the force applied via a ball in the glenoid before the ball dislocated from the glenoid. This stability angle was measured for each of 4 different applied loads. These measurements were repeated after the anteroinferior labrum was augmented by the injection of fresh blood. Injection augmentation of the labrum significantly increased the measured stability angles in 5 of 6 specimens. The 1 outlier had a partial labral tear. The mean increase in stability for all 6 glenoids ranged from 19% to 30% for the different test loads. Labral injection with blood may be a useful adjunct in the surgical management of glenohumeral instability.

Anteroinferior bone-grafting can restore stability in osseous glenoid defects

BACKGROUND

Glenohumeral instability associated with a large osseous defect of the glenoid can be treated with bone graft to restore the glenoid concavity. The shape and positioning of the graft is critical: a graft that encroaches on the extrapolated glenoid curvature can prevent the head from seating completely in the glenoid, whereas a graft that is too far from the curvature does not restore the glenoid concavity. The purpose of the present study was to investigate how the intrinsic stability that is provided by the glenoid is affected by (1) a standardized anteroinferior glenoid defect and (2) different configurations of anteroinferior glenoid bone graft.

METHODS

The anteroinferior stability provided by the glenoid was quantitated by measuring the balance stability angle in that direction. The balance stability angle is the maximal angle that the direction of the net humeral joint-reaction force can make with the glenoid centerline before dislocation takes place. The anteroinferior stability was assessed in each of four fresh-frozen, grossly normal cadaveric glenoids in (1) the unaltered state, (2) after the creation of a standardized defect of a magnitude that has been reported by other investigators to be sufficient to require a bone graft, and (3) after each step of a series of bone-grafting procedures involving grafts of varying height and contour.

RESULTS

The anteroinferior glenoid defect significantly diminished the anteroinferior stability by almost 50% (p = 0.006). Bone-grafting significantly increased the stability provided by the glenoid. The increase in stability as compared with that of the glenoid with the standardized defect was particularly marked for contoured graft heights of 6 and 8 mm, for which the increases were 150% (p = 0.0001) and 229% (p < 0.00025), respectively. Contouring of the graft minimized the potential for unwanted contact between the ball and the graft.

CONCLUSIONS

Anteroinferior shoulder instability caused by an osseous defect in the glenoid can be corrected with bone-grafting. The effectiveness of the graft in restoring the lost stability is related both to its height and to the extent to which it is contoured as long as the graft is not so prominent that it forces the ball posteriorly from the center of the glenoid.