Biomechanical Stability of Diaphyseal Ulnar Shaft Fractures and Ulnar Shortening Osteotomies After Fixation.

BACKGROUND: To determine the amount of micromotion during forearm rotation after diaphyseal ulnar shaft fracture or osteotomy. METHODS: This was a biomechanical study using 7 paired-matched cadavers. The upper extremity was mounted in a custom rig and the forearm brought through full pronation and supination. A Hall effect sensor was placed at the fracture ends to measure micromotion for all tested conditions. There were 4 conditions tested: (1) intact ulnar shaft with plate to act as a control; (2) transverse fracture/osteotomy without stabilization; (3) fracture/osteotomy with cortical apposition stabilized with plate fixation; and (4) 50% comminuted fracture stabilized with plate. RESULTS: There was a significantly greater amount of fracture site motion in the fracture/osteotomy model without stabilization compared with all other tested conditions (P < .001, .0001, .0003, respectively). The fracture/osteotomy site with cortical apposition and the comminuted fracture models showed no statistically significant differences in the amount of micromotion compared with each another (P = .952) or compared with the intact ulnar shaft (P = .997, .889, respectively). CONCLUSIONS: There was no significant difference in the amount of motion between an intact ulnar shaft, an ulnar shaft fracture with cortical apposition stabilized with a plate, and a plated comminuted fracture. These findings may help surgeons decide on their type of postoperative immobilization in the setting of isolated ulnar shaft fractures or ulnar shaft osteotomies stabilized with plate fixation.

Dynamic Computed Tomography of the Distal Radioulnar Joint Versus Magnetic Resonance Imaging in Detecting Foveal Tears of the Triangular Fibrocartilage Complex.

BACKGROUND: Diagnosis of foveal triangular fibrocartilage complex (TFCC) tears remains difficult. The purpose of this study was to evaluate whether dynamic computed tomography (CT) of the distal radioulnar joint (DRUJ) has a higher sensitivity in detecting foveal tears of the TFCC when compared with magnetic resonance imaging (MRI). METHODS: A database query identified all patients above the age of 18 years with suspected foveal TFCC injuries who underwent bilateral dynamic CT imaging of the DRUJ, static 3T MRI, and subsequent wrist arthroscopy. All patients had evidence of foveal tenderness on clinical examination. The imaging results were validated with wrist arthroscopy. RESULTS: Twelve patients with a mean age of 31 years (range, 18-53 years) were identified. Eight patients were diagnosed with a complete foveal detachment of the TFCC on wrist arthroscopy. Of the 8 patients with a foveal tear on DRUJ arthroscopy, only 3 had a preoperative physical examination suggestive of DRUJ instability. Magnetic resonance imaging identified foveal injuries in 4 of these 8 patients (sensitivity, 50%), and 3 of these were identified as only partial tears. Dynamic CT identified instability of DRUJ in 6 of 8 patients (sensitivity, 75%). Seven of 8 patients had imaging findings suggestive of a foveal tear when including either MRI or CT imaging (sensitivity, 88%). Of the 4 patients with an intact foveal attachment on arthroscopy, 3 (specificity, 75%) had a stable DRUJ on CT and all 4 (specificity, 100%) had an intact foveal attachment on MRI. CONCLUSION: Sixty-two percent of patients with foveal tears on arthroscopy have a stable DRUJ on clinical examination. When combining MRI and dynamic CT imaging of the DRUJ, the sensitivity of detecting a foveal TFCC tear approaches 88% compared with a gold standard of wrist arthroscopy.

Volar Wrist Arthroscopy Portals Using the NanoScope Are Safer than Traditional Arthroscopy.

BACKGROUND: The NanoScope, given its smaller size, may be further from critical structures when establishing volar wrist arthroscopy portals compared to the traditional 2.7-mm arthroscope. METHODS: Ten fresh-frozen latex-injected cadaver specimens were utilized. The volar radial (VR) and volar ulnar (VU) portals were created using an inside-out approach. The volar radial midcarpal (VR-MC) and volar ulnar midcarpal (VU-MC) portals were created using an inside-out approach. The arm was then dissected under 3.5-mm loupe magnification. Digital calipers were used to measure the distance between the portals and the surrounding anatomic structures by two fellowship-trained hand surgeons. RESULTS: The median nerve was on average 1.6, 7.2, 1.8, and 5.6 mm away from the trochar for the VR, VU, VR-MC, and VU-MC, respectively. The median nerve fascia was pierced by the VR portal in one specimen. The radial artery, ulnar artery, and ulnar nerve were not pierced in any specimen. Compared to historical controls, for the VR-MC portal, the NanoScope was further from all critical structures, aside from the radial artery, and did not pierce any neurovascular structures. For the VU-MC portal, the NanoScope was further from the ulnar artery and median nerve and did not pierce any neurovascular structures. CONCLUSION: In developing volar portals, after placing the cannula through the volar capsule from an inside-out approach, we recommend making a volar incision and dissecting the local anatomic structures to guard against injury. Compared to historical controls, the NanoScope was typically further from neurovascular structures.

Midterm outcomes of total hip arthroplasty after internal hemipelvectomy and iliofemoral arthrodesis.

BACKGROUND AND OBJECTIVES: Recent studies have reported acceptable outcomes after arthrodesis takedown and conversion to total hip arthroplasty (THA); however, there are no reports on outcomes after oncologic resection, which are inherently complex and may portend poorer outcomes. The purpose of this study was to examine the surgical and functional outcomes of patients who underwent prior hemipelvectomy for tumor resection and were later converted to THA. METHODS: All patients who had prior iliofemoral arthrodesis after oncologic resection that were later converted to THA at a single institution were examined. Charts were reviewed for demographic information, operative information, functional outcomes, and complications/reoperations. RESULTS: All three patients in this study were males who underwent internal hemipelvectomies for chondrosarcoma. Patients were converted to THA at a mean of 26 years after arthrodesis. Mean follow-up after conversion to THA was 7.4 years. During this follow-up period, two of the three patients required revision surgery. At last follow-up, the mean Harris Hip Score was 81 and the mean Mayo Hip Score was 67, and all patients were ambulatory without significant pain. CONCLUSIONS: Overall, patients who undergo iliofemoral arthrodesis after oncologic hemipelvectomy and are later converted to THA can expect to have a reasonable outcome, despite a high rate of complications and revision surgery.

Outcome of Preoperative Asymptomatic or Minimally Symptomatic DRUJ Arthritis after Total Wrist Arthrodesis: A Single-Institution Case Series.

Background Concomitant severe radiocarpal (RC) arthritis with asymptomatic or minimally symptomatic distal radioulnar joint (DRUJ) arthritis can be debilitating for patients. Surgical management of these combined arthritides can pose a dilemma for surgeons and patients. The purpose of this study was to evaluate patients with concomitant RC and DRUJ arthritides who underwent only total wrist arthrodesis (TWA) to determine the need for subsequent surgical management of preoperative asymptomatic/minimally symptomatic DRUJ arthritis. Materials and Methods All patients who underwent TWA between 2008 and 2018 at a single institution were evaluated. Those patients who underwent TWA for degenerative, inflammatory, or posttraumatic arthritis with concomitant asymptomatic or minimally symptomatic DRUJ arthritis preoperatively were included. A retrospective review was performed for demographic variables, TWA indications, pre- versus post-TWA DRUJ symptoms, and severity of DRUJ arthritis on radiographs. Primary outcome measure was survivorship from subsequent DRUJ surgery for development of symptomatic arthritis after initial TWA. Results One hundred and eighty-three patients underwent TWA during the study period, of which 39 wrists met inclusion criteria. Indications for TWA included posttraumatic arthritis ( n = 22), avascular necrosis of the lunate ( n = 10), and inflammatory arthritis ( n = 7). The mean clinical follow-up was 5.7 years (range: 1.5-12.7 years). Four patients (10%) who underwent TWA ultimately required a subsequent procedure to address DRUJ arthritis at a mean time of 20 months (range: 3-60 months) after initial TWA. The initial indication for TWA in these patients included symptomatic posttraumatic arthritis ( n = 3) and lunate avascular necrosis ( n = 1). Conclusion In patients with symptomatic RC and asymptomatic or minimally symptomatic DRUJ arthritides undergoing TWA alone, 10% in this series required subsequent surgical management for progressive DRUJ arthritis. Clinical Relevance Surgical management of concomitant symptomatic RC and asymptomatic/minimally symptomatic DRUJ arthritides with TWA alone is a reasonable initial approach. Patients should be counseled preoperatively that subsequent surgical management of progressive DRUJ arthritis may be necessary in ∼10% of patients.

Surgical management of peroneal nerve injuries.

BACKGROUND: Traumatic peroneal nerve injuries are typically associated with high-energy injuries. The aim of this study was to evaluate the demographics and outcomes following surgical management of peroneal nerve injuries. METHODS: Patients evaluated at a single institution with peroneal nerve injuries between 2001 and 2022 were retrospectively reviewed. Mechanism of injury, time to surgery, pre- and postoperative examinations, and operative reports were recorded. Satisfactory outcome, defined as the ability to achieve anti-gravity dorsiflexion strength or stronger following surgery, was compared between nerve grafting and nerve transfers in patients with at least 9 months of postoperative follow-up. RESULTS: Thirty-seven patients had follow-up greater than 9 months after surgery, with an average follow-up of 3.8 years. Surgeries included neurolysis (n=5), direct repair (n=2), tibial motor nerve fascicle transfer to the anterior tibialis motor branch (n=18), or interposition nerve grafting using sural nerve autograft (n=12). At last follow-up, 59.5% (n=22) of patients had anti-gravity strength or stronger dorsiflexion. Nineteen (51.4%) patients used an ankle-foot orthosis during all or some activities. In patients that underwent nerve grafting only across the peroneal nerve defect, 44.4% (n=4) were able to achieve anti-gravity strength or stronger dorsiflexion. In patients that had a tibial nerve fascicle transfer to the tibialis anterior motor branch of the peroneal nerve, 42.9% (n=6) were able to achieve anti-gravity strength or stronger dorsiflexion at last follow-up. There was no statistical difference between nerve transfers and nerve grafting in postoperative dorsiflexion strength (p = 0.51). CONCLUSION: Peroneal nerve injuries frequently occur in the setting of knee dislocations and similar high-energy injuries. Nerve surgery is not universally successful in restoration of ankle dorsiflexion, with one-third of patients requiring an ankle-foot orthosis at mid-term follow-up. Patients should be properly counseled on the treatment challenges and variable outcomes following peroneal nerve injuries.

Safety of Cubital Tunnel Release Under General versus Regional Anesthesia.

Purpose: The aim of this study was to evaluate the occurrence of early (<6 weeks) post-operative complications following ulnar nerve decompressions at the cubital tunnel performed under regional anesthesia compared to those performed under general anesthesia. Methods: In situ ulnar nerve decompressions at the cubital tunnel performed at a single institution from 2012 through 2019 were retrospectively reviewed. Post-operative complications were compared between subjects who underwent the procedure with regional versus general anesthesia. Results: Ninety-one ulnar nerve in situ decompressions were included in the study, which were performed under regional anesthesia in 55 and general anesthesia in 36 cases. The occurrence of post-operative complications was not significantly different between patients who received regional (n = 7) anesthesia and general (n = 8) anesthesia. None of the complications were directly attributed to the type of anesthesia administered. The change in pre- and post-operative McGowan scores were not significantly different between anesthesia groups (p = 0.81). Conclusion: In situ ulnar nerve decompression at the cubital tunnel under regional anesthesia does not result in increased post-operative complications compared to those surgeries performed under general anesthesia. In situ ulnar nerve decompression performed under regional anesthesia is a safe and reliable option for patients who wish to avoid general anesthesia. Level of Evidence: III.

Optimal hand surgery fellowship interview format.

CONTEXT: The ideal format for residency and fellowship interviews has been consistently debated. Secondary to the COVID-19 pandemic, many institutions, including all hand surgery fellowship programs, transitioned interviews to an all-virtual format. In the past year, with ease of travel restrictions, some programs have transitioned back to in-person interviews, while others remain solely virtual. Hand surgery fellowship programs are continually assessing what are the best means for conducting these interviews, with little perspective regarding the applicant's preferences. OBJECTIVES: The purpose of this study was to examine hand surgery fellowship applicants' perspectives regarding in-person and virtual interviews. It was hypothesized that applicants would value interpersonal relationships between faculty when deciding upon their ideal hand surgery fellowship, which would be easier to appreciate in-person. METHODS: All hand fellowship interviewees at a single institution were given a voluntary, electronic survey. The survey consisted of questions examining different aspects of the program's interview day and supplemental resources. Responses were recorded after the in-person interview for the years 2018-2020. Questions were altered for the virtual 2021 and 2022 interviews. Questions were scored on a Likert scale. RESULTS: For the in-person interview cycles, there were 60/86 respondents (69.8 %). For the virtual interview cycles, there were 45/73 respondents (61.6 %). During the in-person interview cycles, applicants reported that the current fellows' perspective talk was the most helpful component. Many applicants commented that they enjoyed meeting their potential co-fellows. The virtual interviewees felt that they had the best understanding of the program's core values/culture and the worst understanding of faculty personalities and personal/family life. Twenty-nine (64.4 %) of virtual applicants would prefer an all in-person interview. Of the 16 respondents who did not advocate for a completely in-person interview, 56.3 % preferred the option for an in-person site visit. CONCLUSIONS: Hand surgery fellowship applicants desire interpersonal interactions to better understand prospective fellowship programs, which can be difficult to convey with an all-virtual interview. The results of this survey can help guide fellowship programs as they continue to optimize in-person, virtual, and hybrid interview formats and refine recruitment resources.

Painful Fibrous Nonunion of a Posterior Oblique Ligament Bony Avulsion Fracture Associated With Anterior Cruciate Ligament Tear: A Case Report.

CASE: This report describes a case of a posterior oblique ligament (POL) bony avulsion fracture associated with an anterior cruciate ligament (ACL) tear in a 16-year-old female gymnast. The avulsion fracture was discovered on repeat radiographs and magnetic resonance imaging after the patient developed increased pain after ACL reconstruction. After excising the bony avulsion and repairing the POL, she reported complete resolution of her preoperative pain. CONCLUSION: Bony avulsion fractures of the POL are rare and challenging to diagnose. Awareness of this injury and the subtle imaging findings will help clinicians appropriately diagnose and treat these lesions.

Factors Associated with Poorer Outcomes from Triceps Motor Branch to Anterior Axillary Nerve Transfer: A Case-Control Study.

INTRODUCTION: We sought to identify predictors of failed triceps motor branch transfer to the anterior division of the axillary nerve (AN) for shoulder abduction reconstruction after a brachial plexus injury (BPI). METHODS: A case-control study of adult AN or brachial plexus patients treated with a triceps motor branch transfer to the anterior division of the AN with a minimum 18 months of follow-up was performed. The failure group (case group) was defined as modified British Medical Research Council muscle scale (mBMRC) postoperative deltoid grade ≤2 and was compared to the successful outcome group (control group), defined as mBMRC postoperative deltoid grade ≥3. Clinical variables, injury mechanism, time from injury to surgery, root avulsion status, electrodiagnostic studies, rotator cuff injuries, scapula fracture, Disabilities of the Arm Shoulder and Hand scores, and preoperative triceps strength were analyzed. Subgroup analysis was performed for patients with isolated AN injuries and those with BPI. RESULTS: A total of 69 patients met inclusion/exclusion criteria, of whom 23 regained ≥M3 deltoid muscle strength and 52° ± 69° of shoulder abduction (successful outcome group) and 46 regained ≤M2 deltoid muscle strength and 27° ± 30° of shoulder abduction (failure group). Preoperative triceps weakness (M ≤4) was significantly more common in the failure group (63% vs. 30%, P = 0.032); preoperative triceps muscle fibrillations were significantly more common in the failure group (61% vs. 30%, P = 0.02). Isolated AN injuries presented better preoperative motion and postoperative outcomes results compared to BPI. CONCLUSIONS: Use of triceps motor branch associated with fibrillations or weakness resulted in statistically poorer outcomes compared to the use of a normal triceps motor branch in the restoration of anterior AN function after nerve transfer.

CMC Mimickers: Differential Diagnosis and Work-Up for Radial-Sided Wrist Pain.

In patients with radial-sided wrist pain, a myriad of possible etiologies exists and as such, a detailed history, examination, and, where indicated, imaging is obtained to try and aid with its diagnosis. The purpose of this article is to provide an overview of radial-sided wrist pain, diagnostic modalities and discuss current treatment options. More detailed information is out-of-scope for this article and if needed, we would guide the reader to seek out other selected texts, as indicated.

COVID-19 and elective joint arthroplasty: Patient perspectives and considerations.

This study gauged patient perspectives regarding elective joint arthroplasty during the COVID-19 pandemic. Eligible patients undergoing consultation for primary hip or knee arthroplasty received a survey with questions regarding opinions towards COVID-19 and on undergoing elective procedures during the pandemic. Of the 112 respondents, 78% believed that their condition warranted surgery despite COVID-19 circumstances. There were no differences in desire for surgery based on age, smoking history or comorbidities. Patients older than 65 years were significantly more concerned with skilled nursing facility placement. This survey suggests that the majority of patients are comfortable pursuing elective joint arthroplasty despite the pandemic.

Cell cycle-dependent association of polo kinase Cdc5 with CENP-A contributes to faithful chromosome segregation in budding yeast.

Evolutionarily conserved polo-like kinase, Cdc5 (Plk1 in humans), associates with kinetochores during mitosis; however, the role of cell cycle-dependent centromeric ( CEN) association of Cdc5 and its substrates that exclusively localize to the kinetochore have not been characterized. Here we report that evolutionarily conserved CEN histone H3 variant, Cse4 (CENP-A in humans), is a substrate of Cdc5, and that the cell cycle-regulated association of Cse4 with Cdc5 is required for cell growth. Cdc5 contributes to Cse4 phosphorylation in vivo and interacts with Cse4 in mitotic cells. Mass spectrometry analysis of in vitro kinase assays showed that Cdc5 phosphorylates nine serine residues clustered within the N-terminus of Cse4. Strains with cse4-9SA exhibit increased errors in chromosome segregation, reduced levels of CEN-associated Mif2 and Mcd1/Scc1 when combined with a deletion of MCM21. Moreover, the loss of Cdc5 from the CEN chromatin contributes to defects in kinetochore integrity and reduction in CEN-associated Cse4. The cell cycle-regulated association of Cdc5 with Cse4 is essential for cell viability as constitutive association of Cdc5 with Cse4 at the kinetochore leads to growth defects. In summary, our results have defined a role for Cdc5-mediated Cse4 phosphorylation in faithful chromosome segregation.

Polo kinase Cdc5 associates with centromeres to facilitate the removal of centromeric cohesin during mitosis.

Sister chromatid cohesion is essential for tension-sensing mechanisms that monitor bipolar attachment of replicated chromatids in metaphase. Cohesion is mediated by the association of cohesins along the length of sister chromatid arms. In contrast, centromeric cohesin generates intrastrand cohesion and sister centromeres, while highly cohesin enriched, are separated by >800 nm at metaphase in yeast. Removal of cohesin is necessary for sister chromatid separation during anaphase, and this is regulated by evolutionarily conserved polo-like kinase (Cdc5 in yeast, Plk1 in humans). Here we address how high levels of cohesins at centromeric chromatin are removed. Cdc5 associates with centromeric chromatin and cohesin-associated regions. Maximum enrichment of Cdc5 in centromeric chromatin occurs during the metaphase-to-anaphase transition and coincides with the removal of chromosome-associated cohesin. Cdc5 interacts with cohesin in vivo, and cohesin is required for association of Cdc5 at centromeric chromatin. Cohesin removal from centromeric chromatin requires Cdc5 but removal at distal chromosomal arm sites does not. Our results define a novel role for Cdc5 in regulating removal of centromeric cohesins and faithful chromosome segregation.

Pat1 protects centromere-specific histone H3 variant Cse4 from Psh1-mediated ubiquitination.

Evolutionarily conserved histone H3 variant Cse4 and its homologues are essential components of specialized centromere (CEN)-specific nucleosomes and serve as an epigenetic mark for CEN identity and propagation. Cse4 is a critical determinant for the structure and function of the kinetochore and is required to ensure faithful chromosome segregation. The kinetochore protein Pat1 regulates the levels and spatial distribution of Cse4 at centromeres. Deletion of PAT1 results in altered structure of CEN chromatin and chromosome segregation errors. In this study, we show that Pat1 protects CEN-associated Cse4 from ubiquitination in order to maintain proper structure and function of the kinetochore in budding yeast. PAT1-deletion strains exhibit increased ubiquitination of Cse4 and faster turnover of Cse4 at kinetochores. Psh1, a Cse4-specific E3-ubiquitin ligase, interacts with Pat1 in vivo and contributes to the increased ubiquitination of Cse4 in pat1∆ strains. Consistent with a role of Psh1 in ubiquitination of Cse4, transient induction of PSH1 in a wild-type strain resulted in phenotypes similar to a pat1∆ strain, including a reduction in CEN-associated Cse4, increased Cse4 ubiquitination, defects in spatial distribution of Cse4 at kinetochores, and altered structure of CEN chromatin. Pat1 interacts with Scm3 and is required for its maintenance at kinetochores. In conclusion, our studies provide novel insights into mechanisms by which Pat1 affects the structure of CEN chromatin and protects Cse4 from Psh1-mediated ubiquitination for faithful chromosome segregation.