Lucas S. McDonald

Posterior Instability of the Shoulder Diagnosis and Management

Recurrent posterior instability of the shoulder can be difficult to diagnose and technically challenging to treat. Although not as common as anterior instability, recurrent posterior shoulder instability is prevalent among certain demographic and sporting groups, and may be overlooked if one is not aware of the typical examination and radiographic findings. The diagnosis itself can be difficult as patients typically present with vague or confusing symptoms, and treatment has evolved from open to arthroscopic surgical techniques. This article is intended to review the anatomy and biomechanics associated with posterior shoulder instability, to discuss the pathogenesis and presentation of posterior instability, and to describe the variety of treatment options and clinical results.

The Intermetacarpal Angle Screening Test for Ulnar-sided Carpometacarpal Fracture-Dislocations

PURPOSE Ulnar-sided carpometacarpal injuries can be difficult to diagnose radiographically. We hypothesized that the resting position of the normal hand during lateral radiography provides a consistent relationship between the rays and that dorsal subluxation of the metacarpal base in fracture-dislocations increases the angle between the uninjured index and long metacarpals and the injured small metacarpal. METHODS A control group of 100 consecutive patients with normal hand radiographs and a series of 12 patients with known carpometacarpal fracture-dislocations were examined. Angles between the index and small metacarpal shaft (I-S IMA) and between the long and small metacarpal shaft (L-S IMA) were measured on the lateral hand radiograph. RESULTS In the control group, the mean I-S IMA and L-S IMA were both 6°. In the study group, the mean I-S IMA was 18°, and the mean L-S IMA was 16°. Intraobserver and interobserver reliability was good to excellent for both groups, and a statistical difference existed between the normal and study groups. Based on box-plot analysis of normal and abnormal IMAs, a natural dividing line existed at 10°. With this dividing line, the I-S IMA had a sensitivity of 92% and a specificity of 81%, and the L-S IMA had a sensitivity of 83% and a specificity of 84%. CONCLUSIONS Both the I-S IMA and the L-S IMA were useful screening measurements on lateral hand radiographs for detection of ulnar-sided carpometacarpal fracture-dislocations. When evaluating posttraumatic ulnar-sided hand pain, advanced imaging should be considered if the I-S IMA or the L-S IMA is greater than 10°.

A cascade of preventable complications following a missed femoral neck fracture after antegrade femoral nailing

BackgroundOccult femoral neck fractures associated with femoral shaft fractures are frequently missed and may lead to adverse outcomes.Case presentationA 46-year old female presented to our institution with increasing groin pain one month after antegrade intramedullary nailing of a femoral shaft fracture at an outside hospital. Radiographic evaluation revealed a displaced ipsilateral femoral neck fracture, adjacent to the piriformis starting point of the nail. A revision fixation of the femoral shaft and neck fracture was performed. The patient sustained a series of complications requiring multiple revision surgeries, including a total hip arthroplasty. Despite the cascade of complications, the patient had an uneventful long-term recovery, without additional complications noted at one-year follow-up.ConclusionThis case report illustrates the necessity of increased awareness with a high level of suspicion for the presence of associated femoral shaft and neck fractures in any patient undergoing antegrade femoral nailing. Arguably, the cascade of complications presented in this paper could have been prevented with early recognition and initial stabilization of the occult femoral neck fracture. Standardized diagnostic protocols include “on table” pelvic radiographs to rule out associated femoral neck fractures. The diagnosis must be enforced in case of equivocal radiographic findings, either by computed tomography scan or magnetic resonance imaging.

Bilateral Compartment Syndrome of the Anterior Thigh Following Functional Fitness Exercises: A Case Report

We present a case of delayed, acute bilateral exertional compartment syndrome of the anterior thigh induced by callisthenic exercise. Symptoms consisted of pain out of proportion to examination findings, inability to ambulate, and severe pain with knee flexion. Treatment consisted of bilateral thigh fasciotomies and supportive therapy for concomitant rhabdomyolysis. Full strength, range of motion, and return to all military duties were achieved by 4 months postinjury.

Passive Anterior Tibial Subluxation in the Setting of Anterior Cruciate Ligament Injuries: A Comparative Analysis of Ligament-Deficient States:

Background: Static anterior tibial subluxation after an anterior cruciate ligament (ACL) injury highlights the abnormal relationship between the tibia and femur in patients with ACL insufficiency, although causal factors including injuries to secondary stabilizers or the time from injury to reconstruction have not been examined. Purpose: To determine static relationships between the tibia and femur in patients with various states of ACL deficiency and to identify factors associated with anterior tibial subluxation. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients treated for ACL injuries were identified from an institutional registry and assigned to 1 of 4 cohorts: intact ACL, acute ACL disruption, chronic ACL disruption, and failed ACL reconstruction (ACLR). Anterior tibial subluxation of the medial and lateral compartments relative to the femoral condyles were measured on magnetic resonance imaging (MRI), and an MRI evaluation for meniscal tears, chondral defects, and injuries to the anterolateral ligament (ALL) was performed. Results: One hundred eighty-six ACL-insufficient knees met inclusion criteria, with 26 patients without an ACL injury utilized as a control group. In the lateral compartment, the mean anterior tibial subluxation measured 0.78 mm for the control group (n = 26), 2.81 mm for the acute ACL injury group (n = 74), 3.64 mm for the chronic ACL injury group (n = 40), and 4.91 mm for the failed ACLR group (n = 72). In the failed ACLR group, 37.5% of patients demonstrated lateral compartment anterior subluxation ≥6 mm, and 11.1% of this group had anterior subluxation of the lateral compartment ≥10 mm. Multivariate regression revealed that the presence of both medial and lateral chondral defects was associated with a mean 1.09-mm increase in subluxation of the medial compartment (P = .013). The combination of medial and lateral meniscal tears was an independent predictor of increased lateral tibia subluxation by 1.611 mm (P = .0022). Additionally, across all knee states, an injury to the ALL was associated with increased anterior tibial subluxation in both the medial compartment (P = .0438) and lateral compartment (P = .0046). In 29.4% of knees with ALL injuries, lateral tibial subluxation was ≥6 mm, but with multivariate regression analysis, an ALL injury was not an independent predictor of anterior subluxation of the lateral compartment. Conclusion: Knees with failed ACLR are associated with more anterior tibial subluxation than those with primary ACL deficiency. Using previously reported thresholds of 6 to 10 mm of lateral compartment subluxation for a positive pivot shift, between 11.1% and 37.5% of knees with failed ACLR may be in a “resting pivoted position.” In primary ACL-deficient knees, anterior tibial subluxation is associated with chondral injuries and meniscal tears but not injury chronicity.

Epidemiology and Outcomes of Lisfranc Injuries Identified at the National Football League Scouting Combine

Background: Lisfranc injuries are challenging to treat and may have a detrimental effect on athletic performance. Purpose: (1) Determine the epidemiological characteristics of Lisfranc injuries at the annual National Football League (NFL) Scouting Combine, (2) define player positions at risk for these injuries, and (3) evaluate the impact that these injuries and radiographic findings have on NFL draft position and performance. Study Design: Cohort study; Level of evidence, 3. Methods: All players who sustained a Lisfranc injury prior to Combine evaluation between 2009 and 2015 were evaluated. The epidemiological characteristics, player positions affected, treatment methods, and number of missed collegiate games were recorded. Radiographic outcomes were analyzed via Combine radiograph findings, while NFL performance outcomes were assessed for all Lisfranc injuries (2009-2013) compared with matched controls in the first 2 years of play. Results: A total of 41 of 2162 (1.8%) Combine participants were identified with Lisfranc injuries, of whom 26 of 41 (63.4%) were managed operatively. Players who underwent surgery were more likely to go undrafted compared with players managed nonoperatively (38.5% vs 13.3%, operative vs nonoperative management, respectively; P = .04) and featured a worse NFL draft pick position (155.6 vs 109; P = .03). Lisfranc-injured players when compared with controls were noted to have worse outcomes in terms of NFL draft position (142 vs 111.3, Lisfranc-injured players vs controls, respectively; P = .04), NFL career length 2 years or longer (62.5% vs 69.6%; P = .23), and number of games played (16.9 vs 23.3; P = .001) and started (6.8 vs 10.5; P = .08) within the first 2 years of their NFL career. Radiographs demonstrated that 17 of 41 (41.5%) athletes had residual Lisfranc joint displacement greater than 2 mm compared with the contralateral foot. Lisfranc-injured athletes with greater than 2 mm residual displacement, when compared with matched controls, had worse draft position (156.9 vs 111.2 for Lisfranc-injured players vs controls, respectively; P = .009) and fewer games played (14.4 vs 23.3; P = .001) and started (3.1 vs 10.5; P = .03). Moreover, athletes with greater than 2 mm residual displacement featured worse outcomes across all assessed NFL variables versus athletes with residual displacement of 2 mm or less. Conclusion: Lisfranc injuries identified at the NFL Combine have an adverse effect on an NFL athlete’s draft status, draft position, and overall play during initial NFL seasons. In particular, residual displacement of the Lisfranc joint has a detrimental effect on the first 2 seasons of NFL play and may lead to long-lasting negative effects on the athlete’s career.

Surgical Release of the Pectoralis Minor Tendon for Scapular Dyskinesia and Shoulder Pain

Background: Pectoralis minor (PM) tightness has been linked to pain and dysfunction of the shoulder joint secondary to anterior tilt and internal rotation of the scapula, thus causing secondary impingement of the subacromial space. Purpose: To describe outcomes pertaining to nonoperative and operative treatment via surgical release of the PM tendon for pathologic PM tightness in an active population. Study Design: Case series; Level of evidence, 4. Methods: Over a 3-year period, a total of 46 patients were enrolled (mean age, 25.5 years; range, 18-33 years). Inclusion criteria consisted of symptomatic shoulder pain, limited range of overhead motion, inability to participate in overhead lifting activities, and examination findings consistent with scapular dysfunction secondary to a tight PM with tenderness to palpation of the PM tendon. All patients underwent a lengthy physical therapy and stretching program (mean, 11.4 months; range, 3-23 months), which was followed by serial examinations for resolution of symptoms and scapular tilt. Of the 46 patients, 6 (13%) were unable to adequately stretch the PM and underwent isolated mini-open PM release. Outcomes were assessed with scapula protraction measurements and pain scales as well as American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) scores. Results: Forty of the 46 patients (87%) resolved the tight PM and scapular-mediated symptoms with a dedicated therapy program (pre- and posttreatment mean outcome scores: 58 and 91 [ASES], 50 and 90 [SANE], 4.9 and 0.8 [VAS]; P < .01 for all), but 6 patients were considered nonresponders (mean score, 48 [ASES], 40 [SANE], 5.9 [VAS]) and elected to have surgical PM release, with improved scores in all domains (mean score, 89 [ASES], 90.4 [SANE], 0.9 [VAS]; P < .01) at final follow-up of 26 months (range, 25-30 months). Additionally, protraction of the scapula improved from 1.2 to 0.3 cm in a mean midline measurement from the chest wall preoperatively to postoperatively (P < .01), similar to results in nonoperative responders. No surgical complications were reported, and all patients returned to full activities. Conclusion: In most patients, PM tightness can be successfully treated with a nonoperative focused PM stretching program. However, in refractory and pathologically tight PM cases, this series demonstrates predictable return to function with notable improvement in shoulder symptoms after surgical release of the PM. Additional research is necessary to evaluate the long-term efficacy of isolated PM treatment.

Validation of varus stress radiographs for anterior cruciate ligament and posterolateral corner knee injuries: A biomechanical study.

PURPOSE The purpose of this study was to determine the effect of isolated anterior cruciate ligament (ACL) insufficiency on the radiographic varus stress test, and to provide reference data for the increase in lateral compartment opening under varus stress for a combined ACL and PLC injury. METHODS Ten cadaveric lower extremities were fixed to a jig in 20° of knee flexion. Twelve Newton-meter (Nm) and clinician-applied varus loads were tested, first with intact knee ligaments, followed by sequential sectioning of the ACL, fibular collateral ligament (FCL), popliteus tendon and the popliteofibular ligament (PFL). Lateral compartment opening was measured after each sequential sectioning. RESULTS Maximum increase in lateral compartment opening for an isolated ACL deficient knee was 1.06mm with mean increase of 0.52mm (p=0.021) for the clinician-applied load. Mean increase in lateral compartment opening in an ACL and FCL deficient knee compared to the intact knee was 1.48mm (p<0.005) and 1.99mm (p<0.005) for the 12-Nm and clinician-applied loads, respectively, increasing to 1.94mm (p<0.005) and 2.68mm (p<0.005) with sectioning of the ACL and all PLC structures. CONCLUSIONS Anterior cruciate ligament deficiency contributes to lateral compartment opening on varus stress radiographs though not sufficiently to confound previously established standards for lateral ligament knee injuries. We did not demonstrate the same magnitude of lateral compartment opening with sectioning of the PLC structures as previously reported, questioning the reproducibility of varus stress radiographic testing among institutions. Clinicians are cautioned against making surgical decisions based solely on current standards for radiographic stress examinations.

Simultaneous bilateral anterior shoulder fracture dislocation following a seizure: a case report.

Simultaneous, bilateral, anterior dislocations of the glenohumeral joint are rare, most attributable to major trauma. Seizure disorders and electrocution are a common cause of glenohumeral and fracture dislocations although these are most commonly posterior injuries. We present an interesting case report of diagnosis and treatment of an active duty sailor with bilateral anterior shoulder fracture dislocations following a seizure.

Biceps Tenodesis and Intra-articular Decompression for Treatment of Superior Labral Tear from Anterior to Posterior and Associated Paralabral Cyst in Active Duty Military

Background To examine the outcomes of combined biceps tenodesis and indirect, intra-articular arthroscopic paralabral cyst decompression for the treatment of active duty military patients with superior labral from anterior to posterior tears and associated paralabral cysts. Methods Retrospective chart review of all active duty patients at our institution from 2011 to 2014 with superior labral from anterior to posterior tears and associated paralabral cysts at the spinoglenoid notch treated with biceps tenodesis and indirect arthroscopic cyst decompression. Patient charts were examined for pre- and post-operative parameters including strength, range of motion, visual analog scale pain score, American Shoulder and Elbow Surgeon Score, and Single Assessment Numeric Evaluation Score. Results Seven patients met study criteria. All patients presented with chronic shoulder pain and decreased external rotation strength, and three patients had clinically apparent muscular atrophy. Pre- and post-operative assessment showed external rotation strength increased from a median of 4 (range 4-4) to 5 (range 4-5; p-value = 0.014), Single Assessment Numeric Evaluation increased from a median of 50 (range 0-70) to 75 (range 30-95; p-value = 0.031), American Shoulder and Elbow Surgeon increased from a median of 46.0 (range 32.0-58.0) to 66.5 (range 58.0-98.0; p-value = 0.068), and visual analog scale pain score decreased from a median of 3 (range 1-8) to 0 (range 0-5; p-value = 0.017). Median follow-up was 66 wk (range 36-138 wk). The change was statistically significant (p <0.05) for external rotation strength, Single Assessment Numeric Evaluation, and VAS reduction. Post-operatively, all patients returned to full duty at a median of 20 wk (range 12-36 wk). Conclusion The use of biceps tenodesis in conjunction with indirect, intra-articular arthroscopic paralabral cyst decompression is an effective technique in an active patient population with superior labral from anterior to posterior tear with associated paralabral cyst.