Fractional Lengthening of Forearm Flexor Tendons: A Cadaveric Biomechanical Analysis.

PURPOSE: Multiple procedures have been described for wrist and finger flexion contractures and spasticity. Fractional lengthening of forearm flexor tendons involves making parallel transverse tenotomies at the musculotendinous junction to elongate the muscle. Currently, there is limited literature to define the biomechanical consequences of this lengthening technique. METHODS: Forty-eight flexor tendons were harvested from eight paired upper limbs including flexor carpi radialis, flexor carpi ulnaris, flexor pollicis longus, and flexor digitorum superficialis tendons. Each tendon that was lengthened was paired with the contralateral tendon as a control. A pair of transverse tenotomies were completed for the fractional lengthening. The first tenotomy was performed at the musculotendinous junction where the tendon narrowed to 75% of its maximal width. The second tenotomy was made 1 cm distal to the first. Tendon length was measured before and after fractional lengthening at a constant resting tension of 1 N. The maximum load at failure of each tendon and the mechanism of failure were each measured and compared with the contralateral side. RESULTS: After fractional lengthening, the mean increase in resting tendon length was 4 mm. When loaded to failure, the mean maximum load of fractionally lengthened tendons was 42% of the mean maximum load of intact tendons. All lengthened tendons failed at the distal tenotomy site. CONCLUSIONS: Fractional lengthening resulted in an increase of 3-6 mm (mean: 4 mm) in tendon length at resting tension. There was a significant loss in tensile strength and load to failure following fractional lengthening compared with an intact musculotendinous unit. CLINICAL RELEVANCE: The reduction in tensile strength following fractional lengthening results in loads at failure that are, in some cases, lower than the estimated forces required to perform basic tasks. Caution during the healing and rehabilitation period is warranted.

The Influence of Solid Organ Transplant on Inpatient Complications, Length of Stay, and Hospital Costs in Reverse Shoulder Arthroplasty Patients.

INTRODUCTION: With innovations in transplant medicine and longer life expectancies in solid organ transplant (SOT) recipients, the incidence of shoulder arthroplasty is predictably rising in this population. Reverse shoulder arthroplasty (RSA) has become increasingly popular due to advances in prosthetic design with expanded indications. While previous studies have examined shoulder arthroplasty in SOT patients, information specifically related to RSA patients is largely unexplored. We aim to analyze the demographics and characteristics of SOT patients who have undergone RSA while assessing inpatient complication rates, length of stay (LOS), and hospital costs in these patients compared to a matched cohort of non-transplant patients. METHODS: The National Inpatient Sample (NIS) Database was utilized to identify all patients undergoing RSA from 2016 to 2019. We generated propensity-matched groups based on pre-operative variables (diabetes, tobacco use, sex, age, and obesity) to compare complications, LOS, and inpatient costs between the SOT and control groups. T-tests and Chi-squared tests were performed where appropriate and odds ratios were calculated. RESULTS: We identified 59925 patients who underwent RSA. Among those, 59769 patients (99.7%) did not have a SOT and 156 patients (0.26%) had a history of SOT. Patients in the SOT group were younger than the control group (67.0 versus 71.4 years, p<0.001). The SOT group were more likely males compared to the control group (53.8% versus 39.3%, p<0.001). Following 1:1 matching, there were 156 patients in each group. The SOT group had a higher risk of acute renal failure (ARF) compared to the control group (OR 9.41, 95% CI (2.13-41.49), p<0.001). The LOS (p<0.001) and inpatient costs (p<0.001) were higher in the SOT group. CONCLUSION: For RSA, SOT patients are younger and more likely male compared to those without SOT. Inpatient medical and surgical complications are similar between SOT and non-SOT patients, except SOT patients have a higher risk of ARF. SOT patients tend to have longer LOS and higher inpatient costs than non-SOT patients.

Biomechanical Analysis of Headless Compression Screw Versus Tension Band Wiring for Proximal Interphalangeal Joint Arthrodesis.

PURPOSE: Proximal interphalangeal (PIP) joint arthrodesis is a procedure employed to address arthritis, instability, and deformity. Multiple fixation methods are available to maintain stability across the arthrodesis interval, including headless compression screws (HCSs), tension band wiring (TBW), plating, and Kirschner wire constructs. The purpose of this study was to compare the biomechanical properties of the HCS and TBW techniques. METHODS: Thirty-two nonthumb digits from the paired upper limbs of four fresh frozen cadavers were divided into pairs, matching contralateral digits from the same specimen. One PIP joint of each pair was fused with an antegrade 3.5 mm HCS, and the second was fused with TBW using 0.035 in. Kirschner wires with 24-gauge dental wire. Each construct was then stressed to 10 N in the radial deviation, ulnar deviation, flexion, and extension planes, and stiffness (N/mm) was calculated. The fingers were stressed to failure in extension with the ultimate load and mode of failure recorded. RESULTS: When stressed in extension, the HCS construct had a significantly greater mean stiffness than the TBW construct (16.4 N/mm vs 10.8 N/mm). The stiffness in all other planes of motion were similar between the two constructs. The mean ultimate load to failure in extension was 91.4 N for the HCS and 41.9 N for the TBW. The most common mode of failure was fracture of the dorsal lip of the proximal phalanx (13/16) for the HCS and bending of the K-wires (15/16) for TBW. CONCLUSIONS: Arthrodesis of the PIP joint using a HCS resulted in a construct that was significantly stiffer in extension with greater than double the load to failure compared to TBW. CLINICAL RELEVANCE: Although the stiffness required to achieve successful PIP joint arthrodesis has not been well quantified, the HCS proved to be the most favorable construct with respect to initial strength and stability.

Carpal dislocations.

Carpal dislocations result from sequential disruption of the complex relationship between the bones and ligaments of the wrist. Injuries to the carpus occur via predictable mechanisms, an understanding of which is critical to identify and treat these frequently missed patterns of injury and to avoid the sequela of chronic instability. Lunate dislocations are by far the most common, but isolated dislocation of other carpal bones can also occur. Open reduction and internal fixation still remains the gold standard for treatment regardless of the debate around the specific approaches. These high-energy injuries are associated with significant long-term morbidity even when identified promptly and appropriately treated. This review will focus on the evaluation and management of common forms of carpal dislocations.

Comparative Analysis of Unicompartmental Total Knee Arthroplasty and High Tibial Osteotomy: Time to Total Knee Arthroplasty and Other Outcome Measures.

Background: There is no consensus on whether unicompartmental arthroplasty (UKA) or high tibial osteotomy (HTO) is superior for unicompartmental arthritis. While there are studies comparing revision and complication rates, none matched a large number of patients undergoing HTO and UKA in the United States and compared these outcomes. We investigated TKA conversion rate and the complications following HTO or UKA. Methods: This retrospective study queried the PearlDiver database of all patients undergoing UKA and HTO using CPT codes between January 2011 and January 2020. We compared propensity-matched populations based on age, gender, Charlson comorbidity index, and Elixhauser comorbidity index to compare odds of complications, TKA conversion, and drug use between UKA and HTO groups. Two-independent sample t-test for unequal variances and test of significance were performed. Results: We found 32,583 UKA patients and 816 HTO patients. Each matched group had 535 patients. One-year complication showed higher risk of pneumonia, hematoma, infection, and mechanical complications among HTO patients. UKA patients used narcotics on average of 10.3 days compared to 9.1 days among HTO patients (P < .01). UKA conversion rates were 4.1%, 5.4%, 7.7%, and 9.2% at 1-, 2-, 5-, and 10-year intervals, respectively. HTO conversion rates were less than 2% at 1- and 2-year intervals, 3.4% at 5-year, and 4.5% at 10-year intervals. This difference was statistically significant at 5- and 10-year intervals (P < .01). Conclusions: Using large matched cohorts, HTO may be converted to TKA later than UKA in short- to mid-term follow-up, and HTO patients used opioids for shorter duration.

Modified Lapidus Procedure and Hallux Valgus: A Systematic Review and Update on Triplanar Correction.

This review article examines contemporary methods and assesses radiographic outcomes and postoperative complications following the modified Lapidus procedure. A systematic review demonstrated significant improvements in intermetatarsal angle, hallux valgus angle, and tibial sesamoid position. We are updating a modified Lapidus technique for achieving triplanar correction of hallux valgus. Two cases of hallux valgus, one primary and one recurrent, are presented. As demonstrated in the systematic review, outcomes of Lapidus procedures create future opportunities. Surprisingly, only 78% of the studies assessed for this review reported on the hallux valgus angle and only 33% reported on tibial sesamoid position.

Prolonged non-weightbearing treatment decreases femoral head deformity compared to symptomatic treatment in the initial stage of Legg-Calvé-Perthes disease.

The purpose of this study is to investigate the potential benefit of using prolonged non-weightbearing (PNWB) as a treatment option for early-stage Legg-Calvé-Perthes disease (LCPD). An Institutional Review Board (IRB) approved this retrospective study of patients with LCPD and ≥2-year follow-up. Patients 6-12 years of age were included if treatment began in Waldenstrom stage 1 or 2A. PNWB consisted of ≥6 months of non- or toe-touch weightbearing. PNWB was recommended if perfusion MRI demonstrated ≥40% hypoperfusion of the femoral head and parents decided against operative treatment. The control group consisted of symptomatically treated patients. Deformity index and epiphyseal quotient were measured at 2-year follow-up. Stulberg classification and sphericity deviation score (SDS) were determined at skeletal maturity or at a minimum of 5-year follow-up. When treatment was initiated in Waldenstrom stage 1, the PNWB group had significantly less femoral head deformity, including deformity index (0.21 vs. 0.52; P < 0.001), epiphyseal quotient (69% vs. 43%; P < 0.001), SDS (18 vs. 52; P = 0.004), and Stulberg (50% good vs. 0% good; P = 0.044). The PNWB group mean hypoperfusion was 68%, indicating severe hypoperfusion. Duration of recommended non-weight bearing in the PNWB group was 11.5 months (range 7-17 months). Despite severe femoral head hypoperfusion, PNWB begun during the initial stage of LCPD decreased femoral head deformity. PNWB should be considered a treatment option for patients/parents who do not wish to pursue operative intervention in early-stage LCPD with substantial hypoperfusion. Level of Evidence III - retrospective comparative study.

Moderate Weightbearing Restrictions Are Associated with Worse Depressive Symptoms and Anxiety in Children Aged 5 to 7 Years with Perthes Disease.

BACKGROUND: Perthes disease most commonly affects children 5 to 7 years old, and nonoperative management, such as weightbearing and activity restrictions, is generally recommended. In earlier research in children aged 8 to 14 years who had Perthes disease, we found that the restrictions were associated with worse mobility, but mental health or social health measures were not linked. However, Perthes disease most commonly affects children 5 to 7 years old who are more emotionally and cognitively immature. Children in this age group are beginning school and organized sports experiences while developing meaningful social relationships for the first time. Because of such different life experiences, it is important to understand the psychosocial consequences of weightbearing and activity restrictions on this specific age group, as they may help guide choices about weightbearing restrictions and mental health support. QUESTIONS/PURPOSES: In patients aged 5 to 7 years with Perthes disease, we asked: (1) Are weightbearing and activity restrictions associated with worse mental health, evaluated with the Patient-reported Outcome Measurement Information System (PROMIS) depressive symptoms, anxiety, and anger questionnaires? (2) Are weightbearing and activity restrictions associated with worse social health (PROMIS peer relationships measure)? (3) Are weightbearing and activity restrictions associated with worse physical health measures (PROMIS mobility, pain interference, and fatigue measures)? (4) What other factors are associated with mental, social, and physical health measures in these patients? METHODS: Data were collected from 97 patients with a diagnosis of Perthes disease. Inclusion criteria were age 5 to 7 years at the time the PROMIS was completed, English-speaking patients and parents, in the active stage of Perthes disease (Waldenstrom Stages I, II, or III) who were recommended weightbearing and activity restrictions because of worsening hip pain, poor hip ROM, femoral head deformity, as a postoperative regimen, or if there was substantial femoral head involvement on MRI [23]. Based on their weightbearing and activity restriction regimen, patients were categorized into one of four activity restriction groups (no, mild, moderate, and severe restriction). The following pediatric parent-proxy PROMIS measures were obtained: depressive symptoms, anxiety, anger, peer relationships, mobility, pain interference, and fatigue. We excluded five patients who did not meet the inclusion criteria. Of the remaining 92 patients, 21 were in the no restriction group, 21 were in the mild restriction group, 28 were in the moderate restriction group, and 22 were in the severe restriction group at the time of PROMIS administration. ANOVA was used to compare differences between the mean PROMIS T-scores of these four groups. T-scores are computed from PROMIS survey responses, and a T-score of 50 represents the age-appropriate mean of the US population with an SD of 10. A higher T-score means more of that measure is being experienced and a lower score means less of that measure is being experienced. To address the possibility of confounding variables such as Waldenstrom stage, gender, age at diagnosis, and history of major surgery, we performed a multivariable analysis to compare the association of different weightbearing regimens and the seven PROMIS measures. This allowed us to answer the question of whether weightbearing and activity restrictions are associated with worse physical, mental, and social health measures in Perthes patients aged 5 to 7 years, while minimizing the possible confounding of the variables listed above. RESULTS: After controlling for confounding variables such as Waldenstrom stage, gender, age at diagnosis, and history of major surgery, we found that moderate activity restriction was associated with worse depressive symptoms (ß regression coefficient = 6 [95% CI 0.3 to 12]; p = 0.04) and anxiety (ß = 8 [95% CI 1 to 15]; p = 0.02) T-scores than no restrictions. The mild (ß = -7 [95% CI -12 to -1]; p = 0.02), moderate (ß = -15 [95% CI -20 to -10]; p < 0.001), and severe (ß = -23 [95% CI -28 to -18]; p < 0.001), restriction groups had worse mobility T-scores than the no restriction group. Weightbearing and activity restrictions were not associated with anger, peer relationships, pain interference, and fatigue measures. Waldenstrom Stage II disease was associated with worse pain interference than Waldenstrom Stage III (ß = 7 [95% CI 0.4 to 13]; p = 0.04). A history of major surgery was associated with worse anger scores (ß = 18 [95% CI 3 to 33]; p = 0.02). The child's gender and age at diagnosis had no association with any of the seven PROMIS measures. CONCLUSION: Moderate weightbearing and activity restrictions are associated with worse depressive symptoms and anxiety in patients with Perthes disease aged 5 to 7 years, after controlling for Waldenstrom stage, gender, age at the time of diagnosis, and history of surgery. Considering the discoveries in this study and in our previous study, for patients 5 to 7 years old, we recommend that providers discuss the potential for mental health changes with moderate weightbearing restrictions with patients and their families. Furthermore, providers should monitor for worsening mental health symptoms at each follow-up visit and refer patients to a clinical child psychologist for support when appropriate. Future studies are needed to assess the effects of these restrictions on mental health over time and after patients are allowed to return to normal activities. LEVEL OF EVIDENCE: Level III, therapeutic study.

Weightbearing and Activity Restriction Treatments and Quality of Life in Patients with Perthes Disease.

BACKGROUND: Weightbearing and activity restrictions are commonly prescribed during the active stages of Perthes disease. These restrictions, ranging from cast or brace treatment with nonweightbearing to full weightbearing with activity restrictions, may have a substantial influence on the physical, mental, and social health of a child. However, their impact on the patient's quality of life is not well-described. QUESTIONS/PURPOSES: After controlling for confounding variables, we asked (1) are restrictions on weightbearing and activity associated with physical health measures (as expressed by the Patient-Reported Outcome Measurement Information System [PROMIS] mobility, PROMIS pain interference, and PROMIS fatigue) of children in the active stages of Perthes disease? (2) Are these restrictions associated with poorer scores for mental health measures (PROMIS depressive symptoms and PROMIS anxiety)? (3) Are these restrictions associated with poorer scores for social health measures (PROMIS peer relationships)? METHODS: Between 2013 and 2020, 211 patients with Perthes disease at a single institution were assigned six PROMIS measures to assess physical, mental, and social health. Patients who met the following eligibility criteria were analyzed: age 8 to 14 years old, completion of six PROMIS measures, English-speaking, and active stage of Perthes disease (Waldenstrom Stage I, II, or III). Weightbearing and activity restrictions were clinically recommended to patients in the initial through early reossification stages of Perthes disease when patients had increasing pain, loss of hip motion, loss of hip containment, progression of femoral head deformity, increased hip synovitis, and femoral head involvement on MRI or as a postoperative regimen. Patients were categorized into four intervention groups based on weightbearing and activity regimen. We excluded 111 patients who did not meet the inclusion criteria. The following six pediatric self-report PROMIS measures were assessed: mobility, pain interference, fatigue, depressive symptoms, anxiety, and peer relationships. Of the 100 patients, 36 were categorized into the no-restriction regimen, 27 into the mild-restriction regimen, 25 into the moderate-restriction regimen, and 12 into the severe-restriction regimen at the time of PROMIS administration. The median (range) age at diagnosis was 8 years old (range 2 to 13 years). There were 85 boys and 15 girls. Eleven patients had hips in Waldenstrom Stage I, 10 were in Stage II, and 79 were in Stage III. Forty-four patients had hips classified as lateral pillar B and 47 patients as lateral pillar C. Nine patients had not reached the mid-fragmentation stage for appropriate lateral pillar classification by the time they took the PROMIS survey. ANOVA was used to compare differences between the mean PROMIS T-scores of these weightbearing/activity regimens. Results were assessed with a significance of p < 0.05 and adjusted for Waldenstrom stage, gender, age at diagnosis, and history of major surgery using multivariate regression analysis. RESULTS: After controlling for confounding variables, the mild- (ß regression coefficient -15 [95% CI -19 to -10]; p < 0.001), moderate- (ß -19 [95% CI -24 to -14]; p < 0.001), and severe- (ß -25 [95% CI -30 to -19]; p < 0.001) restriction groups were associated with worse mobility T-scores compared with the no-restriction group, but no association was detected for the pain interference or fatigue measures. Weightbearing and activity restrictions were not associated with mental health measures (depressive symptoms and anxiety). Weightbearing and activity restrictions were not associated with social health measures (peer relationships). Earlier Waldenstrom stage was associated with worse pain interference (ß 10 [95% CI 2 to 17]; p = 0.01) and peer relationships scores (ß -8 [95% CI -15 to -1]; p = 0.03); female gender was linked with worse depressive symptoms (ß 7 [95% CI 2 to 12]; p = 0.005) and peer relationships scores (ß -6 [95% CI -12 to 0]; p = 0.04); and earlier age at diagnosis was associated with worse peer relationships scores (ß 1 [95% CI 0 to 2]; p = 0.03). History of major surgery had no connection to any of the six PROMIS measures. CONCLUSION: We found that weightbearing and activity restriction treatments are associated with poorer patient-reported mobility in the active stages of Perthes disease after controlling for Waldenstrom stage, gender, age at diagnosis, and history of surgery. Weightbearing/activity restrictions, however, are not associated with pain interference, fatigue, depressive symptoms, anxiety, and peer relationships. Understanding how these treatments are associated with quality of life in patients with Perthes disease can aid in decision-making for providers, help set expectations for patients and their parents, and provide opportunities for better education and preparation. Because of the chronic nature of Perthes disease, future studies may focus on longitudinal trends in patient-reported outcomes to better understand the overall impact of this disease and its treatment. LEVEL OF EVIDENCE: Level III, therapeutic study.

Characterization of a Thiol-Ene/Acrylate-Based Polymer for Neuroprosthetic Implants.

Thiol-ene/acrylate shape-memory polymers can be used as base substrates for neural electrodes to treat neurological dysfunction. Neural electrodes are implanted into the body to alter or record impulse conduction. This study characterizes thiol-ene/acrylate polymers to determine which synthesis methods constitute an ideal substrate for neural implants. To achieve a desired Tg between 50 and 56.5 °C, curing conditions, polymer thickness, monomer ratios, and water uptake were all examined and controlled for. Characterization with dynamic mechanical analysis and thermal gravimetric analysis reveals that thin, thiol-ene/acrylate polymers composed of at least 50 mol % acrylate content and cured for at least 1 h at 365 nm are promising as substrates for neural electrodes.