Dave R. Shukla

Stress Shielding Around Radial Head Prostheses

PURPOSE Stress shielding is known to occur around rigidly fixed implants. We hypothesized that stress shielding around radial head prostheses is common but nonprogressive. In this study, we present a classification scheme to support our radiographic observations. METHODS We reviewed charts and radiographs of 86 cases from 79 patients with radial head implants from both primary and revision surgeries between 1999 and 2009. Exclusion criteria included infection, loosening, or follow-up of less than 12 months. We classified stress shielding as: I, cortical thinning; II, partially (IIa) or circumferentially (IIb) exposed stem; and III, impending mechanical failure. RESULTS Of 26 well-fixed stems, 17 (63%) demonstrated stress shielding: I = 2, II = 15 (IIa = 12, IIb = 3), and III = 0. We saw stress shielding with all stem types: cemented or noncemented; long or short; and straight, curved, or tapered. The only significant difference was that stems implanted into the radial shaft had less stress shielding than stems implanted into the neck or tuberosity (P = .03). The average follow-up was 33 months (range, 13-70 mo). Stress shielding was detectable by an average of 11 months (range, 1-15 mo). The pattern of bone loss was similar in 16 of 17 cases (94%), starting on the outer periosteal cortex. The 3 cases with circumferential exposure of the stem (stage IIb) averaged 2.6 mm (range, 1-4 mm) of exposed stem. Stress shielding never extended to the bicipital tuberosity, and there were no cases of impending mechanical failure. CONCLUSIONS Stress shielding around radial head prostheses is common, regardless of stem design. However, it is typically minor, nonprogressive, and of questionable clinical consequence. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.

Hemiarthroplasty versus reverse shoulder arthroplasty for treatment of proximal humeral fractures: a meta-analysis

BACKGROUND We performed a meta-analysis of studies with at least Level IV evidence to compare outcomes between hemiarthroplasty and reverse shoulder arthroplasty for the treatment of proximal humeral fractures. METHODS Three electronic databases (PubMed, Cochrane, and EMBASE) were searched. The quality of each study was investigated, and data on radiographic and functional outcomes were extracted and analyzed. RESULTS The analysis included 1 Level I study, 1 Level II study, 3 Level III studies, and 2 Level IV studies. Reverse shoulder arthroplasty was more favorable than hemiarthroplasty in forward elevation (P < .001), abduction (P < .001), tuberosity healing (P = .002), Constant score (P < .001), American Shoulder and Elbow Surgeons score (P < .001), and Disabilities of the Arm, Shoulder and Hand score (P = .001). Only external rotation (P = .85) was not in favor of reverse shoulder arthroplasty. CONCLUSIONS The available literature suggests that reverse shoulder arthroplasty performed to address complex proximal humeral fractures might result in more favorable clinical outcomes than hemiarthroplasty performed for the same indication.

Heterotopic ossification formation after fracture-dislocations of the elbow.

BACKGROUND Heterotopic ossification (HO) is a serious complication of traumatic elbow injuries, particularly fracture-dislocations. Limited data exist in the literature regarding the risk factors associated with HO formation in these injuries. The purpose of this study was to review the incidence of HO after fracture-dislocation of the elbow and to identify potential risk factors associated with its formation. METHODS Twenty-seven patients (28 elbows) were surgically treated for elbow fracture-dislocations during 8 years, with an average follow-up of 14 months. Records were reviewed with attention paid to several factors: demographic data, comorbidities, time interval from injury to surgical intervention, number of closed reductions attempted before surgery, surgical approach, management of the radial head, treatment of the anterior capsular injury, and coronoid fixation. RESULTS Of the 28 elbows, 12 (43%) developed HO postoperatively; 9 of 28 elbows underwent multiple attempted closed reductions before definitive surgical stabilization, with HO formation in 7 of the 9 (77%). Time to surgery, age, gender, radial head fixation or replacement, coronoid open reduction and internal fixation, capsular repair, and medical comorbidities were not found to influence HO formation, although the performance of multiple reductions was identified as a risk factor. DISCUSSION HO developed in 77% of patients with multiple attempted closed reductions. We found a 43% incidence of HO in patients surgically treated for elbow fracture-dislocations. Neither time to surgery after the injury nor demographic or other factors relating to the manner in which associated osseous or soft tissue injuries were managed influenced the formation of HO.

Importance of the posterior bundle of the medial ulnar collateral ligament

BACKGROUND There has been a renewed interest in the pathomechanics of elbow dislocation, with recent literature having suggested that the medial ulnar collateral ligament is more often disrupted in dislocations than the lateral ligamentous complex. The purpose of this serial sectioning study was to determine the influence of the posterior bundle of the medial ulnar collateral ligament (pMUCL) as a stabilizer against elbow dislocation. METHODS An elbow dislocation was simulated in 5 cadaveric elbows by mechanically applying an external rotation moment and valgus force. Medial ulnohumeral joint gapping was measured at 30°, 60°, and 90° of flexion in an intact elbow after sectioning of the medial collateral ligaments anterior bundle (aMUCL) and then after sectioning of the pMUCL as well. RESULTS After sectioning of the aMUCL, the pMUCL was able to stabilize the joint against dislocation. After aMUCL sectioning, the proximal joint space significantly increased by 4.2 ± 0.6 mm at 30° of flexion and 2.6 ± 0.3 mm at 60° of flexion, although it did not dislocate. The gapping increase of 0.9 ± 0.6 at 90° of flexion did not reach significance. After sectioning of the pMUCL (after having already sectioned the aMUCL), all of the specimens frankly dislocated at all flexion angles. CONCLUSIONS An intact pMUCL can prevent elbow dislocation and limited joint subluxation to within 6.6 mm. Our findings indicate that repair or reconstruction may be warranted in certain circumstances (ie, residual instability after operative management of a terrible triad injury or after aMUCL reconstruction).

A novel approach for coronoid fractures.

The coronoid process serves as an important constraint that provides ulnohumeral joint stability. We describe a novel approach to coronoid fractures that minimizes surgical dissection, without compromising fracture visualization. We present the case of a 65-year-old woman who sustained an anteromedial facet fracture of the coronoid process. The elbow demonstrated intractable posteromedial instability and the inability to maintain reduction even up to 90 degrees. This report describes a surgical approach to the coronoid process that minimizes extensive soft tissue dissection. It is a variation of the previously described approach by Taylor and Scham, although it can achieve a similar exposure without elevation of the entirety of the flexor-pronator mass. Our approach involves a limited skin incision, followed by elevation of enough of the flexor-pronator mass such that adequate visualization of the posterior medial collateral ligament (which was repaired), anteromedial facet, and the fractured fragment of coronoid were achieved. Moreover, this approach enables the course of the ulnar nerve to remain unaltered.

The Posterior Bundle’s Effect on Posteromedial Elbow Instability After a Transverse Coronoid Fracture: A Biomechanical Study

PURPOSE There has been increased interest in the role of the posterior bundle of the medial collateral ligament (pMUCL) in the elbow, particularly its effects on posteromedial rotatory stability. The ligaments effect in the context of an unfixable coronoid fracture has not been the focus of any study. The purposes of this biomechanical study were to evaluate the stabilizing effect of the pMUCL with a transverse coronoid fracture and to assess the effect of graft reconstruction of the ligament. METHODS We simulated a varus and internal rotatory subluxation in 7 cadaveric elbows at 30°, 60°, and 90° elbow flexion. The amount of ulnar rotation and medial ulnohumeral joint gapping were assessed in the intact elbow after we created a transverse coronoid injury, after we divided the pMUCL, and finally, after we performed a graft reconstruction of the pMUCL. RESULTS At all angles tested, some stability was lost after cutting the pMUCL once the coronoid had been injured, because mean proximal ulnohumeral joint gapping increased afterward by 2.1, 2.2, and 1.3 mm at 90°, 60°, and 30°, respectively. Ulnar internal rotation significantly increased after pMUCL transection at 90°. At 60° and 30° elbow flexion, ulnar rotation increased after resection of the coronoid but not after pMUCL resection. CONCLUSIONS An uninjured pMUCL stabilizes against varus internal rotatory instability in the setting of a transverse coronoid fracture at higher flexion angles. Further research is needed to optimize graft reconstruction of the pMUCL. CLINICAL RELEVANCE The pMUCL is an important secondary stabilizer against posteromedial instability in the coronoid-deficient elbow. In the setting of an unfixable coronoid fracture, the surgeon should examine for posteromedial instability and consider addressing the pMUCL surgically.

Subscapularis Repair After Shoulder Arthroplasty

Both anatomic and reverse total shoulder arthroplasty have demonstrated excellent results in patients with arthritis. The deltopectoral approach is commonly utilized for both procedures, and the subscapularis is typically taken down. Multiple variations of subscapularis repairs are known, but subscapularis failure postoperatively can lead to poor clinical outcomes. We present a case of a standard anatomic total shoulder arthroplasty subscapularis repair with a specific suture configuration and a metallic button. In this technique, both Krackow and Mason-Allen suture techniques are utilized to approximate the tendon down to the bone. The patient described recovered quickly after the surgery, and he has demonstrated excellent results. These results are similar to those seen by the senior author while utilizing this technique, and after transitioning to this technique, postoperative subscapularis failures have been infrequently appreciated.

The Influence of Incision Type on Patient Satisfaction After Plate Fixation of Clavicle Fractures

Background: Open reduction and internal fixation (ORIF) of the clavicle is a common procedure that has been shown to have improved outcomes over nonoperative treatment. Several incisions can be used to approach clavicle fractures, the decision of which is variable among surgeons. Purpose: To compare patient satisfaction and subjective outcomes between patients with a longitudinal incision versus those with a necklace incision for the treatment of diaphyseal clavicle fractures. Study Design: Cohort study; Level of evidence, 3. Methods: Thirty-six patients with a diaphyseal clavicle fracture (Orthopaedic Trauma Association type 15-B) were treated by 1 of 7 orthopaedic surgeons. The intervention was ORIF with anatomic contoured plates. Patients were divided into a necklace incision group and a longitudinal incision group depending on the surgical approach used. Medical records were reviewed, and participants completed an online survey with questions related to pain, numbness, scar appearance, and satisfaction. Function was assessed using the American Shoulder and Elbow Surgeons score. Statistical significance was determined with P < .05. Results: There were 16 patients in the necklace incision group and 20 in the longitudinal incision group. Patients in the necklace incision group were significantly more satisfied with the appearance of their scars (P = .01), which correlated with overall satisfaction (P = .05). There were no differences in overall satisfaction, pain, numbness, or reoperation rates for hardware removal between the necklace (6%) and longitudinal groups (15%). Conclusion: Patients undergoing clavicle ORIF with a necklace incision are more satisfied with their scar appearance than those with a longitudinal incision. The overall satisfaction, rate of numbness, and plate removal were similar in both groups.

The results of tension band rotator cuff suture fixation of locked plating of displaced proximal humerus fractures

INTRODUCTION The purpose of this study was to assess 1-year outcomes of patients with displaced proximal humerus fractures who underwent treatment with locked plate fixation with rotator cuff suture augmentation. METHODS A total of 86 patients who had sustained 2, 3 and 4-part displaced proximal humerus fractures underwent locked plate fixation with multiple sutures placed in the cuff tendons. Clinical outcome variables included active forward elevation (AFE), active external rotation (AER), and Constant and American Shoulder and Elbow Surgeons (ASES) scores. Post-operative variables included the following complications: varus re-collapse, loss of fixation, osteonecrosis of the humeral head (AVN), screw cut out, hardware failure and infection. RESULTS Forty-one patients were available with minimum of 1-year follow-up. Mean AFE was 142±17.0° and AER was 41±13.0°. The overall complication rate was 14.6%, with osteonecrosis being the most common (12.2%). Of the 21 patients (51.2%) that initially had varus displacement, all but one maintained anatomic reduction and fixation. Mean ASES score was 78.2±20.0 and average Constant score was 72.7±17.6. Bivariate analyses demonstrated that pre-operative medial comminution (p=0.297) or varus collapse (p=0.95) were not associated with an increased likelihood of sustaining a complication. CONCLUSIONS Follow-up of patients in this series demonstrated a low overall complication rate and excellent functional outcomes. We believe suture augmentation of the rotator cuff can counteract varus forces on proximal humerus fractures fixed with locked plates, and should be performed routinely in displaced 2, 3 and 4 part fractures.