Outcomes and Return to Sport After Knee Osteochondral Allograft Transplant in Professional Athletes.

Background: Limited data are available on the outcomes and return-to-sport rates after osteochondral allograft transplant in professional athletes. Purpose: To evaluate the experience of a single senior surgeon in treating professional athletes with osteochondral allograft transplant, including analyzing clinical outcomes and return to sport. Study Design: Case series; Level of evidence, 4. Methods: The authors performed a retrospective review of professional athletes treated with primary osteochondral allograft to the knee between January 1, 2001, and January 1, 2021, by a single surgeon. Athletes were required to play at the professional level in their sport and have a minimum of 2 years of follow-up. Return-to-sport rates and timing were evaluated. Patient-reported outcomes were assessed preoperatively and at final follow-up. Reoperations and failures were also tabulated. Results: The study included 15 professional athletes who represented a variety of sports, with follow-up at a mean of 4.91 ± 2.2 years (range, 2.0-9.4 years). The majority (8 athletes; 53%) had undergone prior surgeries to the operative knee. Eleven (73%) returned to sport at a mean of 1.22 ± 0.4 years (range, 0.75-2 years), and of the 8 undergoing isolated osteochondral allograft, 7 (87.5%) returned at 1.28 ± 0.3 years. Ten athletes (66.7% of total; 90.9% of those who returned) returned to sport at the same level or higher compared with before surgery. Significant improvements were seen in each assessed patient-reported outcome score at final follow-up. Two of the 3 (66.7%) patients who underwent concomitant meniscal allograft transplant were able to return to sport at the same level or higher than presurgery. Three (20%) underwent second-look arthroscopy, 1 (6.7%) of whom underwent cartilage debridement of the osteochondral allograft. Conclusion: Osteochondral allograft transplant in professional athletes can result in a high rate of return to play at a similar or higher level as presurgery, even when performed with concomitant procedures such as meniscal allograft transplant. High-level athletes should expect significant postoperative improvement in clinical outcomes.

Bioabsorbable Screw Fixation Provides Good Results With Low Failure Rates at Mid-term Follow-up of Stable Osteochondritis Dissecans Lesions That Do Not Improve With Initial Conservative Treatment.

Purpose: To evaluate the clinical and radiographic outcomes of patients who have undergone bioabsorbable screw fixation for intact, stable grade I and II osteochondritis dissecans (OCD) lesions for which at least 6 months of conservative management has failed. Methods: A retrospective review of prospectively collected data from a single institution was performed to identify patients who underwent internal fixation of stable grade I and II OCD lesions (according to the Guhl classification) between January 2010 and January 2020. Patients were included regardless of the presence of concomitant procedures. The inclusion criteria consisted of (1) primary surgery, (2) failure of at least 6 months of conservative management, (3) the use of a bioabsorbable screw (or screws), and (4) minimum 2-year clinical follow-up. Radiographs were obtained at a minimum of 1 year postoperatively. Patient demographic characteristics, clinical patient-reported outcomes, complications, and failure rates were noted. Results: Twenty-four knees among 23 patients (96% follow-up) were analyzed and followed up for 6.36 ± 3.42 years (range, 2.0-12.7 years). Patients showed statistically significant postoperative improvements in all patient-reported outcomes including the Lysholm score, International Knee Documentation Committee score, and Knee Injury and Osteoarthritis Outcome Score subscales (P < .05). In 3 knees (12%), a reoperation was required due to failure at an average of 3.64 years after the index procedure. No specific complications were attributed to the use of bioabsorbable screws. Patients in whom primary surgical treatment failed did not differ in demographic characteristics, arthroscopic findings, or surgical treatment from those who had successful treatment. Conclusions: Internal fixation of stable grade I and II OCD lesions with bioabsorbable screws produces reliable results with a 12% rate of failure in appropriately indicated patients in whom at least 6 months of conservative management has failed. Clinical outcomes improved significantly during the mid-term follow-up period. Level of Evidence: Level IV, therapeutic case series.

Revision and Conversion to Arthroplasty Are Low Among Adolescents Undergoing Meniscal Allograft Transplantation Using the Bridge-In-Slot Technique at Midterm Follow-Up.

PURPOSE: To report midterm outcomes after primary medial and lateral meniscal allograft transplantation (MAT) with fresh-frozen allografts implanted with the bridge-in-slot technique in the adolescent patient population. METHODS: Adolescent patients less than 18 years old at the time of primary MAT from 1999 to 2016 were retrospectively identified. International Knee Documentation Committee (IKDC) subjective form, Lysholm, and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales scores were collected before surgery and at 1-year, 2-year, and a minimum 5-year follow-up. Thresholds for achieving clinically significant outcomes were calculated, and the proportion of patients achieving minimal clinically important difference (MCID), patient-acceptable symptomatic state (PASS), and substantial clinical benefit (SCB) was determined. Meniscus reoperation (partial, subtotal, or total meniscectomy, repair, or failure) and failure (revision MAT or conversion to arthroplasty) rates were determined. RESULTS: Forty-four (female n = 33; male n = 11) of 62 identified patients met inclusion criteria and were followed for a mean of 9.5 ± 3.8 years (range, 5.0-17.7). Lateral MAT was performed in most patients (n = 35/44 [80%]). Isolated MAT was performed in 27 (61%) patients. Common concomitant procedures included osteochondral allograft transplantation (32%), autologous chondrocyte implantation (18%), and anterior cruciate ligament reconstruction (14%). MCID, PASS, and SCB were achieved by patients at a minimum 5-year follow-up for IKDC (62%; 76%; 31%), Lysholm (62%; 79%; 23%), and KOOS questionnaires (Pain [65%; 81%; 41%], Symptoms [58%; 81%; 47%], Activities of Daily Living [53%; 77%; 35%], Sport [86%; 75%; 50%], and Quality of Life [59%; 81%; 59%]), respectively. Fourteen patients (32%) underwent reoperation at an average of 5.0 ± 4.3 years (range, 0.8-14.0) after MAT. Three (7%) patients met criteria for failure, requiring revision MAT an average of 3.8 ± 1.1 years (range, 2.8-4.9) after transplantation. No patients underwent arthroplasty. Overall survival free from failure at 1, 2, 5, and 10 years was 100%, 100%, 93%, and 93%, respectively. At the time of final follow-up, 80% of patients reported satisfaction with their current physical status. CONCLUSIONS: Primary MAT in adolescent patients resulted in significant and durable functional improvements at mid- to long-term follow-up. At an average of 9.5 years after surgery, meniscal reoperation rate was 32% whereas graft survival free of revision MAT was 93%. Adolescents undergoing MAT demonstrated similar functional outcomes and graft survivability when compared to available adult MAT literature. LEVEL OF EVIDENCE: Level IV, retrospective case series.

One to Two Days of Rest Is Recommended Before Returning to Sport After Intra-Articular Corticosteroid Injection in the High-Level Athlete.

Return to sport following a corticosteroid injection is a complex decision. Multiple considerations should be taken into account, including steroid dose and formulation, involvement of the affected joint in the activity, and intensity of the activity. Research investigating the adverse effects of corticosteroid injections with early initiation of high-intensity activity is limited and has produced mixed results. Rest following injections has typically been recommended to minimize both chondrotoxic effects and systemic absorption. Based on the current research and extensive experience treating professional athletes, we recommend 1 to 2 days of rest of the affected joint or region with a progressive increase of activity following a corticosteroid injection with possible benefits including maximizing the beneficial effects of the injection and a reduced systemic effect. Level of Evidence: Level V, expert opinion.

Orthopaedic Musculoskeletal Biologics Research Impacts Patient Care: The First Annual Arthroscopy Orthobiologics Virtual Special Issue.

Orthobiologics can modify symptoms and improve healing in a variety of musculoskeletal conditions as a part of office-based care or as an adjunct to surgery. Orthobiologics harness the benefits of naturally derived blood components, autologous tissue, and growth factors to reduce inflammation and optimize the host-healing environment. The Arthroscopy family of journals seeks to positively influence evidence-based clinical decision-making by publishing peer-reviewed biologics research. This special issue contains recent influential articles strategically chosen to positively impact patient care.

The Effect of Locking Screws on Distal Component Fixation in Total Wrist Arthroplasty Using a Cadaver Model.

Purpose: The advent of total wrist arthroplasty has allowed for motion-sparing surgical treatment for wrist arthritis. The Integra Freedom Total Wrist Arthroplasty recently incorporated locking caps into its distal component fixation to minimize implant micromotion and improve osseous integration. The purpose of this study was to assess the kinematic effect of locking caps in a cadaveric model. Methods: The Integra Freedom was implanted in 4 matched-pair cadavers and tested with and without the use of the locking caps, with the testing order randomized. Each specimen was tested on a custom testing system in a position of 15° of radial deviation, neutral position, and 15° of ulnar deviation with 25 N, 50 N, 75 N, and 100 N of compressive force. The rotation of the capitate, trapezoid, and hamate at all positions was measured using a 3-dimensional digitizer. Results: Statistical analysis showed no difference in carpal rotation between the nonlocking cap and locking cap groups at all testing loads and wrist positions. The absolute motion of the distal row was minimal. However, of the total 216 loads/positions tested, only 4 (1.8%) showed a rotation of greater than 2° and only 34 (15.7%) showed a rotation of greater than 1°. Conclusions: This study shows that in a time zero cadaveric model, the initial osseous fixation of the distal component in the Integra Freedom is robust with or without locking caps. The addition of locking caps did not have a kinematic effect on distal carpal row fixation. However, further investigation into its clinical role is necessary. Clinical Relevance: At time zero, there is minimal carpal motion after implantation of the Integra Freedom Total Wrist with functional loading. The addition of locking caps did not lead to any decrease in carpal motion.

Editorial Commentary: Rotator Cuff Repair: Graft Augmentation Provides Promising Clinical Outcomes.

Rotator cuff repair has benefitted from many technologic advances including the advent of arthroscopy, improved implant materials, and refined repair techniques. Despite our efforts to improve the science of rotator cuff repair, clinical advances have lagged far behind. Graft augmentation of rotator cuff repairs is an emerging and heterogeneous field that has significantly improved both healing rates and patient-reported metrics in initial data reporting. Treatment algorithms that guide the use of this novel surgical modality are of benefit to practicing orthopaedic surgeons.

Moderate Return to Play and Previous Performance After SLAP Repairs in Competitive Overhead Athletes: A Systematic Review.

PURPOSE: To perform a systematic review of return to play (RTP) and return to previous level of performance (RPP) in competitive overhead athletes after SLAP repair to identify factors associated with failure to RTP. METHODS: Systematic review was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Review was registered with PROSPERO International prospective register of systematic reviews (CRD42020215488). Inclusion criteria were literature reporting RTP or RPP following SLAP repair in overhead athletes were run in the following databases: PubMed/MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Google Scholar. Categories for data collection for each full article included (1) article information; (2) patient demographics; (3) surgical techniques; (4) level of competition; (5) rotator cuff treatment; (6) player position; (7) patient-reported outcome measures; and (8) RTP and RPP rates. The Methodological Index for Non-randomized Studies checklist was used to evaluate quality of all included studies. RESULTS: Eight studies with 333 subjects were identified. Overall RTP and RPP rates were 50% to 83.6% and 35.3% to 64%, respectively. Patients with surgically treated rotator cuff pathology had lower RTP (12.5%-64.7%) rates compared with those without (80.0%-83.6%). Professional athletes had similar RTP rates (62.5%-81.5%) compared with high-school (75.0%-90.0%) and college athletes (12.5%-83.3%). However, professional athletes demonstrated the lowest relative range of reported RPP rates (27.7%-55.6%). Pitchers had lower RTP (62.5%-80.0%) and RPP (52.0%-58.9%) compared with position players (91.3% RTP, 76.3%-78.2% RPP). CONCLUSIONS: Studies reviewed reported moderate RTP and RPP rates following SLAP repairs in competitive overhead athletes. Those with associated rotator cuff tear requiring treatment, and baseball pitchers were less likely to RTP and RPP. Professional athletes had similar RTP to an amateur; however, they were less likely to RPP. LEVEL OF EVIDENCE: Level IV, systematic review of Level III-IV studies.

New Approaches to the Diagnosis and Management of Periprosthetic Joint Infection of the Shoulder.

Periprosthetic joint infection (PJI) of the shoulder is a potentially devastating complication following shoulder arthroplasty. It is important to review the workup of PJI in the shoulder, including recently developed diagnostic criteria for shoulder PJI, along with detailed examination of the most common causative organism, Cutibacterium acnes. Treatment strategies for PJI of the shoulder include antibiotic therapy, surgical options, and what to do with unexpected positive cultures in revision arthroplasty. Surgeons should be familiar with bony and soft-tissue reconstructive options following explantation of an infected shoulder prosthesis.

Early clinical and radiographic outcomes of anatomic total shoulder arthroplasty with a biconvex posterior augmented glenoid for patients with posterior glenoid erosion: minimum 2-year follow-up.

BACKGROUND: Glenoid bone loss in anatomic total shoulder arthroplasty (aTSA) remains a controversial and challenging clinical problem. Previous studies have shown high rates of glenoid loosening for aTSA in shoulders with retroversion, posterior bone loss, and posterior humeral head subluxation. This study is the first to present minimum 2-year follow-up data of an all-polyethylene, biconvex augmented anatomic glenoid component for correction of glenoid retroversion and posterior humeral head subluxation. METHODS: This study is a multicenter, retrospective review of prospectively collected data on consecutive patients from 7 global clinical sites. All patients underwent aTSA using the biconvex posterior augmented glenoid (PAG). Inclusion criteria were preoperative computed tomographic (CT) scan, minimum 2 years since surgery, preoperative and minimum 2-year postoperative range of motion examination, and patient-reported outcome measures (PROMs). Glenoid classification, glenoid retroversion, and posterior humeral head subluxation were measured from preoperative CT and radiography and postoperative radiography. Statistical comparisons between pre- and postoperative values were performed with a paired t test. RESULTS: Eighty-six of 110 consecutive patients during the study period (78% follow-up) met the inclusion criteria and were included in our analysis. Mean follow-up was 35 ± 10 months, with a mean age of 68 ± 8 years (range 48-85). Range of motion statistically improved in all planes from pre- to postoperation. Mean visual analog scale score improved from 5.2 preoperation to 0.7 postoperation, Single Assessment Numeric Evaluation score from 43.2 to 89.5, Constant score from 41.8 to 76.9, and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score from 49.8 to 86.7 (all P < .0001). Mean glenoid retroversion improved from 19.3° to 7.4° (P < .0001). Posterior subluxation improved from 69.1% to 53.5% and posterior decentering improved from 5.8% to -3.0% (P < .0001). There was 1 patient with both a prosthetic joint infection and radiographic glenoid loosening that required revision. Seventy-nine of 86 patients had a Lazarus score of 0 (no radiolucency seen about peg or keel) at final follow-up. CONCLUSIONS: This study shows that at minimum 2-year follow-up, a posterior-augmented all-polyethylene glenoid can correct glenoid retroversion and posterior humeral head subluxation. Clinically, there was significant improvement in both range of motion and PROMs.

Rotator Cuff Repair with Graft Augmentation Improves Function, Decreases Revisions, and Is Cost-Effective.

PURPOSE: The purpose of this study is to evaluate the cost effectiveness of the use of extracellular matrix (ECM) augment at the time of primary rotator cuff repair utilizing a decision tree analysis. METHODS: A decision tree model was created utilizing the existing literature for retear rates with and without dermal graft augmentation. Costs for rotator cuff repair (hospital and surgeon fees) were based on published studies and the cost for graft augmentation was based on institutional data. Utility measures were based upon EQ-5D (European Quality of Life 5 Dimension) scores to assess for improvement in quality adjusted life years (QALY) over a 10-year postoperative period with and without graft augmentation. Cost effectiveness was assessed using the incremental cost effectiveness ratio (ICER), or the incremental cost for per QALY with graft augmentation. Cost effectiveness is based on previous literature whereby an intervention is considered cost effective if the ICER is less than $50,000/QALY. RESULTS: On the basis of our decision tree analysis, total cost for rotator cuff tear without augmentation was $12,763, while the cost increased to $16,039 with ECM augmentation. With graft augmentation there was an improvement in 2.29 QALY, while there was an improvement of 2.05 without graft augmentation. The ICER of graft augmentation is $14,000/QALY, well below the cost effectiveness cut-off of $50,000/QALY. Sensitivity analysis showed the maximum cost of the ECM augment to be cost effective is $11,921. CONCLUSION: Graft augmentation does come with a significant upfront cost; however, on the basis of our decision-tree analysis, it may represent a cost-effective procedure. There is evidence to potentially consider more routine use in rotator cuff repairs, while being cost effective. LEVEL OF EVIDENCE: Economic: Level IV: computer simulation model (Monte Carlo simulation, Markov model) with inputs derived from Level IV studies.

Comparison of mechanical properties between Nice knot, Modified Nice knot, and surgeon's knot.

BACKGROUND: The success of surgical repairs rely on the effectiveness and integrity of the surgical knots used to secure the repair. The purpose of this study is to examine and compare the performance of the Nice knot, the modified Nice knot, and a commonly used combination of surgeons' and square knots with respect to cyclic loading and load-to-failure usiflueng a high-strength suture composed of ultra-high molecular weight polyethylene in the hands of experienced surgeons. METHODS: Two experienced surgeons threw 3 different knot types 9 times, consisting of the Nice knot, modified Nice knot, and a surgeon's knot utilizing Ultrabraid #2 sutures. Each knot was subject to cyclic loading and load to failure testing. FINDINGS: Both surgeons had similar displacement data for the surgeon's knot, while the identity of the surgeon impacted displacement for the Nice knot (p = 0.03) and the modified Nice knot (p = 0.0002). The load to failure for the modified Nice knot (p < 0.001) and the Nice knot (p = 0.001) were significantly impacted by the surgeon tying the knot, while the surgeon's knot was not. Specimens failed where the sutures passed through the loop at the "base" of the knot. INTERPRETATIONS: The strength and integrity of complex surgical knots are variable between surgeons. While the proposed Modified Nice Knot has a theoretical advantage because the half hitches reinforce the primary knot, in load to failure testing both the Modified Nice Knot and the Nice Knot failed where the suture passed through the loop in the primary knot.

Racial Disparities Affecting Postoperative Outcomes After Brain Tumor Resection.

OBJECTIVE: To investigate racial disparities in 30-day postoperative outcomes of craniotomy for glioma resection. METHODS: 2006-2019 American College of Surgeons' National Surgical Quality Improvement Program files were queried for all patients who underwent a craniotomy for a supratentorial glioma resection. Racial disparities in preoperative variables were studied between the demographic cohorts of Asian, African Americans, Hispanics, and Caucasian. Fisher exact tests were used to examine association of preoperative variables with race. Multivariable logistic regression models, adjusted for all preoperative variables associated with race, were used to determine the odds ratios of postoperative outcomes for each demographic cohort in comparison with Caucasian patients. RESULTS: A total of 12,544 patients were identified: 4% Asian, 5% African American, 7% Hispanic, and 85% Caucasian. African American patients had significantly higher adjusted odds than Caucasian patients of major adverse cardiovascular events (adjusted odds ratio [aOR]: 1.827, 95% confidence interval [CI]: 1.155-2.891, P = 0.01), pulmonary events (aOR: 1.683, 95% CI: 1.145-2.473, P = 0.008), and urinary tract infection (aOR: 2.016, 95% CI: 1.221-3.327, P = 0.006). Asian patients had significantly higher odds than Caucasian patients of requiring a transfusion (aOR: 2.094, 95% CI: 1.343-3.266, P = 0.001). All demographic cohorts had higher odds of having an extended length of stay than Caucasian patients. CONCLUSIONS: African American patients who undergo a craniotomy for glioma resection have almost twice the odds of Caucasian patients of having a postoperative major cardiovascular complication, pulmonary complication, or urinary tract infection. All minority groups have higher odds of an extended length of stay as compared with Caucasian patients.

Penetrating Thoracoabdominal Trauma With a Cryptic Diaphragmatic Injury in a 23-Year-Old Male.

Traumatic diaphragmatic injuries are a rare entity and can occur in relation to penetrating thoracic and abdominal trauma. The most common clinical features of diaphragm rupture include chest or abdominal bruising, decreased breath sounds, and signs of bowel obstruction. However, the classic signs and symptoms of diaphragmatic injury are not always present and can be obscured even in the highest resolution imaging. This highlights the importance for maintaining a high index of suspicion to make the diagnosis and properly manage these patients. Here, we present a rare case of a 23-year-old male who experienced a laceration to his left thorax and was later discovered to have concurrent diaphragmatic injury despite an initially noncontributory physical exam and imaging findings. The patient subsequently underwent robotic repair of the injury and reduction of herniated contents.

A Complicated Case of Postpartum Myasthenic Crisis.

Myasthenia gravis (MG) is the most common autoimmune disorder affecting the neuromuscular junction (NMJ) of voluntary skeletal muscle. This disease is characterized by ptosis, diplopia, facial muscle weakness, bulbar muscle involvement including dysphagia and difficulty chewing, dysarthria, hypophonia, respiratory muscle fatigue, and sometimes generalized weakness. A myasthenic crisis (MC) is a complication of MG. MC is defined as severe worsening of respiratory function necessitating the need for mechanical ventilation. Precipitating factors include infection, certain drugs, pregnancy, childbirth, surgery, discontinuation of medical therapy, or even spontaneously with no inciting event. Here we present a complicated case of a 24-year-old patient with a long history of controlled who encounters many events that lead to an MC necessitating mechanical intubation, plasmapheresis, and high dose immunosuppressive therapy. She recently gave birth to a child, had an occult perforated appendicitis with multiple abscesses needing emergent exploratory laparotomy, and had an overlying COVID-19 infection. The complexity of this disease and its complications warrants careful consideration by physicians in any branch of specialty.

Jaw Pain and Profound Bradycardia - An Atypical Presentation of Lyme Carditis.

In 2018, 23,558 confirmed cases and 10,108 probable cases of Lyme disease were reported in the United States, with 96% of all cases coming from 14 states. Lyme carditis is well described, occurring in less than 1% of Lyme disease. High-grade heart block is uncommon in early disseminated Lyme disease. In Lyme carditis due to sinus node dysfunction and/or high grade atrioventricular block, the pulse rates are significantly lower which can lead to syncope. This can happen in the setting of an unstable ventricular escape rhythm with pulse rates ranging around 30 beats per minute or lower. In patients with low cardiovascular reserve, high-degree AV block can cause sudden death. Here we describe a rare case of profound bradycardia in disseminated Lyme disease. The patient's only two symptoms are bradycardia and jaw pain. He lacks erythema migrans, neurological symptoms or syncope - despite having high-degree AV block. Initially prescribed doxycycline 100mg BID, his PR interval begins to normalize, but once a Lyme titre was positive for IgM (p41, p39, p23) and IgG (p66, p45, p41, p39, p23, p18), the patient was switched to 2g ceftriaxone IV Q 24h, per Infectious Disease Society of America (IDSA) guidelines. After several days he feels better and was discharged home to complete antibiotics and wear a cardiac event monitor. Lyme disease has three distinct stages that include early localized infection, early disseminated disease, and late infection. At the time of Lyme carditis diagnosis, common symptoms include erythema migrans, malaise, polyarthritis, Bell's palsy and other neurological symptoms - all of which were lacking in our patient. The prognosis for Lyme carditis is generally good, despite disagreement over the incidence of persistent B. burgdorferi infection. This patient's unique presentation of Lyme carditis is further evidence of variability in cardiac symptoms depending on one's immunological and physiological ability to combat acute spirochete infection.

Biomechanical Evaluation of Unilateral Versus Bilateral C1 Lateral Mass-C2 Intralaminar Fixation.

STUDY DESIGN: Biomechanical, cadaveric study. OBJECTIVES: To compare the relative stiffness of unilateral C1 lateral mass-C2 intralaminar fixation to intact specimens and bilateral C1 lateral mass-C2 intralaminar constructs. METHODS: The biomechanical integrity of a unilateral C1 lateral mass-C2 intralaminar screw construct was compared to intact specimens and bilateral C1 lateral mass-C2 intralaminar screw constructs. Five human cadaveric specimens were used. Range of motion and stiffness were tested to determine the stiffness of the constructs. RESULTS: Unilateral fixation significantly decreased flexion/extension range of motion compared to intact (P < .001) but did not significantly affect axial rotation (P = .3) or bending range of motion (P = .3). There was a significant decrease in stiffness in extension for both unilateral and bilateral fixation techniques compared to intact (P = .04 and P = .03, respectively). There was also a significant decrease in stiffness for ipsilateral rotation for the unilateral construct compared to intact (P = .007) whereas the bilateral construct significantly increased ipsilateral rotation stiffness compared to both intact and unilateral fixation (P < .001). CONCLUSION: Bilateral constructs did show improved biomechanical properties compared to the unilateral constructs. However, unilateral C1-C2 fixation using a C1 lateral mass and C2 intralaminar screw-rod construct decreased range of motion and improved stiffness compared to the intact state with the exception of extension and ipsilateral rotation. Hence, a unilateral construct may be acceptable in clinical situations in which bilateral fixation is not possible, but an external orthosis may be necessary to achieve a fusion.

Anatomic Posterolateral Corner Reconstruction Using a Fibula Cross-Tunnel Technique: A Cadaveric Biomechanical Study.

PURPOSE: To compare the biomechanical properties of a fibula cross-tunnel technique for posterolateral corner (PLC) reconstruction with those of intact knees. METHODS: Seven fresh-frozen cadaveric knees were tested while intact, after PLC tear, and after reconstruction. Testing of the parameters listed above was performed at 0°, 30°, 60°, and 90° of knee flexion. Reconstruction was performed using 2 independent tendon autografts. Afterward, the fibula and graft were loaded to failure. RESULTS: Reconstruction restored external rotation (0°: 11.75° ± 2.02° to 9.81° ± 1.81°, P = .57; 30°: 17.91° ± 1.32° to 13.96° ± 2.84°, P = .12; 60°: 15.86° ± 1.68° to 13.26° ± 3.58°, P = .41; 90°: 15.53° ± 1.62° to 14.07° ± 2.95°, P = .54) to the intact state, and posterior translation (0°: 3.66 ± 0.85 mm to 3.31 ± 0.89 mm, P = .87; 60°: 3.15 ± 0.45 mm to 2.96 ± 0.45 mm, P = .73; 90°: 2.74 ± 0.33 mm to 3.05 ± 0.41 mm, P = .41) and varus angulation (0°: 0.92° ± 0.35° to 1.98° ± 0.42°, P = .55; 30°: 2.65° ± 0.27° to 1.09° ± 0.90°, P = .37; 90°: 4.29° ± 0.44° to 2.53° ± 1.13°, P = .19) under most conditions. During load to failure testing, the construct revealed properties similar to those of native structures (yield load: 330.4 ± 45.8 N; ultimate load: 420.9 ± 37.4 N). CONCLUSIONS: This technique restored external rotation to the intact state after PLC injury in all testing conditions, as well as posterior translation at 0°, 60°, and 90° of flexion, and varus angulation under all conditions tested except 60° of flexion. CLINICAL RELEVANCE: Clinically, this surgical technique may eliminate the need for a tibial tunnel for posterolateral corner reconstruction.

The effects of prosthetic humeral head shape on glenohumeral joint kinematics during humeral axial rotation in total shoulder arthroplasty.

BACKGROUND: A non-spherical humeral head has been shown to influence kinematics and stability of the glenohumeral joint; yet, most prosthetic humeral head components are designed to be a perfect sphere. The effect of humeral head shape on prosthetic joint kinematics after total shoulder arthroplasty is not well understood. We hypothesized that prosthetic joint kinematics during humeral axial rotation is dependent on humeral head shape, regardless of joint conformity. METHODS: Four prosthetic configurations were investigated using a spherical and a non-spherical prosthetic humeral head articulated with a conforming and a non-conforming glenoid component. Testing was performed in the coronal, scapular, and forward flexion plane at 0°, 30°, and 60° of abduction. Prosthetic joint kinematics was measured in 10° intervals during a 100° arc of humeral axial rotation. Glenohumeral translation patterns, net glenohumeral translation, and averaged glenohumeral translation were compared for each of 4 configurations. RESULTS: Non-spherical head configurations increased the net glenohumeral translation during humeral axial rotation in multiple test positions compared with spherical head configurations (P < .05). Spherical head configurations resulted in a relatively small amount of glenohumeral translation, less than 2 mm. The radius of curvature of the glenoid component alone did not affect the net glenohumeral translation within each of the 2 head groups (P > .05). CONCLUSION: During humeral axial rotation, the non-spherical humeral head shape contributes to increased glenohumeral translation during humeral axial rotation. However, the spherical head shape does not show significant glenohumeral translation during humeral axial rotation, regardless of glenoid conformity.

The effect of long and short head biceps loading on glenohumeral joint rotational range of motion and humeral head position.

PURPOSE: To evaluate the effect of loading the long and short heads of the biceps on glenohumeral range of motion and humeral head position. METHODS: Eight cadaveric shoulders were tested in 60° abduction in the scapula and coronal plane. Muscle loading was applied based on cross-sectional area ratios. The short and long head of the biceps were loaded individually followed by combined loading. Range of motion was measured with 2.2 Nm torque, and the humeral head apex position was measured using a MicroScribe. A paired t test with Bonferroni correction was used for statistics. RESULTS: Long head loading decreased internal rotation in both the scapular (17.9 %) and coronal planes (5.7 %) and external rotation in the scapular plane (2.6 %) (P < 0.04). With only short head loading, maximum internal rotation was significantly increased in the scapular and coronal plane. Long head and short head loading shifted the humeral head apex posteriorly in maximum internal rotation in both planes with the long head shift being significantly greater than the short head. Long head loading also shifted the humeral apex inferiorly in internal rotation and inferiorly posteriorly in neutral rotation in the scapular plane. With the long head unloaded, there was a significant superior shift with short head loading in both planes. CONCLUSION: Loading the long head of the biceps had a much greater effect on glenohumeral range of motion and humeral head shift than the short head of the biceps; however, in the absence of long head loading, with the short head loaded, maximum internal rotation increases and the humeral head shifts superiorly, which may contribute to impingement following tenodesis of the long head of the biceps. These small changes in rotational range of motion and humeral head position with biceps tenodesis may not lead to pathologic conditions in low-demand patients; however, in throwers, biceps tenodesis may lead to increased contact pressures in late-cocking and deceleration that will likely translate to decreased performance therefore every effort should be made to preserve the biceps-labral complex.