Mesenchymal PLAG1 Tumor With PCMTD1-PLAG1 Fusion in an Infant: A New Type of "Plagoma".

ABSTRACT: In the past decade, there have been major advances in knowledge related to mesenchymal tumors, and new genetic alterations are being delineated. We report a mesenchymal spindle cell neoplasm harboring a novel gene fusion in an infant. Histopathologically, the neoplasm shared some features with sclerosing perineurioma, but immunohistochemically, EMA was negative, whereas GLUT1, NK1-C3, and BCOR were positive. Next-generation sequencing revealed a PCMTD1-pleomorphic adenoma gene 1 (PLAG1) fusion. PLAG1 contributes to the expression of a variety of genes implicated in regulating cell proliferation, and PCMTD1 has been related to the development of certain carcinomas. Recently, other soft tissue tumors in young children associated with PLAG1 fusion variants have been reported. Perhaps, mesenchymal neoplasms presenting PLAG1 fusions with different genes would confirm a specific group (PLAG mesenchymal tumours or "plagomas") in the near future.

Does Patient Sex Affect Ultrasound Cutoff Values for Severity Grading of Carpal Tunnel Syndrome?

PURPOSE: A growing body of evidence supports ultrasound (US) as an alternative first-line confirmatory test for carpal tunnel syndrome (CTS). Recent studies have demonstrated a correlation of US cross-sectional area with electrodiagnostic (EDX)-determined severity; however, it is unclear whether patient sex affects the cutoff values used for determining severity. The purpose of this study was to determine if patient sex affects US graded severity when using EDX as the reference standard. METHODS: A cohort of 367 women and 46 men, aged 18-90 years, from 1 orthopedic hand surgeon's practice underwent EDX and US. Distal motor latency and distal sensory latency of the median nerve were recorded. Severity was classified using a modified Bland severity scale. The US measurements of the cross-sectional area of the median nerve at the wrist crease were acquired by a fellowship-trained hand surgeon. Separate receiver operator characteristic curve analyses of the male and female groups were performed for US cutoff values. RESULTS: The cutoff value in both the female (F) and male (M) patients was 11 mm2 for mild (area under the curve = 0.76 F; 0.78 M), 12 mm2 for moderate (area under the curve = 0.75 F; 0.73 M), and 13 mm2 for severe (area under the curve = 0.75 F; 0.71 M) CTS. The sensitivity of the cutoffs for mild, moderate, and severe CTS in the female and male groups was 49% and 56%, 44% and 50%, and 49% and 44%, respectively. The specificity of the cutoffs for mild, moderate, and severe CTS in the female and male groups was 75% and 79%, 74% and 82%, and 83% and 78%, respectively. CONCLUSIONS: Patient sex does not appear to have a significant impact on the determination of CTS severity graded using US cutoff values. Ultrasound can be used to grade the severity of CTS with a 75% to 85% specificity but low sensitivity. A cutoff value of 13 mm2 can be used to classify CTS as severe. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

False-Positive Rates for Nerve Conduction Studies and Ultrasound in Patients Without Clinical Signs and Symptoms of Carpal Tunnel Syndrome.

PURPOSE: The purpose of the study was to determine the rate of false positives for nerve conduction studies (NCSs) and ultrasound (US) in a population without signs and symptoms of carpal tunnel syndrome (CTS) using a CTS-6 score of 0 as the reference standard. METHODS: Patients were included in this study if they were referred for NCSs for a reason other than CTS (cubital tunnel syndrome and/or cervical radiculopathy) and they had a CTS-6 score of 0. An US measurement of the cross-sectional area (CSA) of the median nerve at the level of the carpal tunnel inlet was performed by a certified ultrasound technician. An a priori CSA cutoff of 10 mm2 or greater measured using US at the carpal tunnel inlet qualified as a positive diagnosis. The NCSs were performed and interpreted according to national standards by a certified electrodiagnostician. All patients in this study were considered to not have a diagnosis of CTS based on the CTS-6 of 0. RESULTS: Forty hands with a CTS-6 of 0 were included in this study. The US was positive in 9 of 40(23%) and NCS was positive in 17 of 40 (43%). There were only 2 patients with a false-positive US that did not also have a positive NCS. However, there were 11 patients who had a false-positive NCS that did not have a positive US. CONCLUSIONS: This prospective cohort series has demonstrated that US has a lower false-positive rate than NCSs in asymptomatic patients as measured by the CTS-6 diagnostic tool. Studies with a low false-positive rate are preferred when ordering a confirmatory diagnostic test. Therefore, if a confirmatory diagnostic test is desired, we recommend that US be used rather than NCSs. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

A Prospective Comparison of Diagnostic Tools for the Diagnosis of Carpal Tunnel Syndrome.

PURPOSE: Nerve conduction studies (NCS), CTS-6, Wainner, Kamath, and Lo are diagnostic tests that are used to diagnose carpal tunnel syndrome (CTS). To our knowledge, no study has compared the sensitivity and specificity of these 5 tests with one another. The purpose of this study is to compare NCS, CTS-6, Wainner, Kamath, and Lo using clinical diagnosis by a hand fellowship-trained orthopedic surgeon as reference standard. METHODS: A hand fellowship-trained surgeon completed the CTS-6, Wainner, Kamath, and Lo diagnostic tools. Cutoff values for a positive test were based on values in the literature, if available. The NCS were performed by a certified electrodiagnostic physician according the standards of the American Association of Neuromuscular and Electrodiagnostic Medicine and were interpreted using absolute latencies, relative latencies, and combined sensory index. Sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were calculated for the tests using clinical diagnosis as the reference standard. RESULTS: A total of 408 wrists from 250 patients were analyzed in the study. The NCS had the highest sensitivity (94%) but also the lowest specificity (50%) of any of the diagnostic tests. Using a cutoff of 18, CTS-6 had the highest specificity (99%). The NCS had the highest area under the curve at 74%, followed closely by the Kamath at 69%. CONCLUSIONS: The NCS were traditionally felt to be a strong confirmatory test given their high specificity. However, this prospective series demonstrated that NCS had the lowest specificity of any diagnostic test. CLINICAL RELEVANCE: Consideration should be given to using alternative diagnostic tests/tools based on the results of this study.

Anatomy of the flexor digitorum profundus insertion.

PURPOSE: To describe the anatomical insertion of the flexor digitorum profundus (FDP) on the distal phalanx. METHODS: The FDP insertion to the index, middle, ring, and little fingers were dissected in 10 fresh-frozen cadavers. The FDP tendon was dissected off the volar plate, which was elevated from proximal to distal, before the distal phalanx was disarticulated. The distal phalanx was then inked and the FDP was sharply dissected from bone. The insertion length, width, and distance of the insertion from the joint were measured and the insertion surface area and centroid of the FDP insertion were calculated. RESULTS: The average insertion length and width were 6.2 mm (range, 5.1-7.0 mm) and 7.9 mm (range, 6.9-8.4 mm), respectively. The average surface area of the distal phalanx occupied by the FDP tendon, for all fingers, was 20% (range, 15%-27%). The average distance from the most proximal insertion to the joint surface was 1.2 mm (range, 0.4-2.1 mm) and the calculated centroid of the FDP insertion from the distal interphalangeal joint was 3.6 mm (range, 2.5-5.1 mm) or approximately 20% of the distal phalangeal length. CONCLUSIONS: These findings may aid anatomical attachment of the FDP tendon in the treatment of zone I injuries. CLINICAL RELEVANCE: A better understanding of the anatomy of the FDP insertion may aid proper repair positioning in the treatment of zone I injuries.

A Comparison of Plain Radiographs and Computed Tomography for Determining Canal Diameter of the Distal Phalanx.

PURPOSE: To compare plain radiographs and computed tomography (CT) when determining the narrowest diameter of the medullary canal of the distal phalanx. METHODS: A database review identified 48 patients (23 male, 25 female) who underwent a CT scan of the hand and plain radiographs of the same hand. Using digital imaging software, the smallest diameter of the medullary canal was measured for each finger (index, middle, ring, little) on CT and on radiographs. RESULTS: The narrowest diameter of the medullary canal was measured on the axial CT and lateral hand radiograph at the transition between the tuft and the distal phalanx shaft. The mean narrowest diameters on plain radiographs for the index, middle, ring, and little fingers were 1.4 mm, 1.4 mm, 1.4 mm, and 1.1 mm, respectively. The mean diameters on CT were 1.2 mm, 1.3 mm, 1.2 mm, and 1.0 mm, respectively. Men had larger medullary canal dimensions (1.5-1.7 mm) than women (0.8-1.2 mm). CONCLUSIONS: The differences in canal diameter measurements between plain radiograph and CT were small and likely clinically insignificant. CLINICAL RELEVANCE: Lateral radiographs can be used for preoperative planning when estimating the size of the distal phalanx intramedullary canal.

Biologic strategies to improve nerve regeneration after peripheral nerve repair.

BACKGROUND: Peripheral nerve injuries remain a challenging problem for microsurgeons. Direct repair is the gold standard, but often the surgeon is left with a gap that prevents tension-free repair. The use of empty tubes/conduits/allograft has resulted in regeneration of some sensory and motor function, but the results remain suboptimal compared with autograft. However, the use of nerve autograft has associated donor site morbidity and limited availability. METHODS: A review of the literature was performed to determine current biologic strategies to improve nerve regeneration after nerve repair. RESULTS: Nerve conduits, various neurotrophic factors, and stem cells are currently being studied as alternatives to the use of nerve autograft. CONCLUSIONS: Sensory and motor recovery after peripheral nerve regeneration remains suboptimal, especially in cases where primary nerve repair is not possible. Current strategies to augment nerve regeneration have focused on modulating the presence and activity of Schwann cells, either through direct implantation or by stimulating stem cells to differentiate toward Schwann cells, and through the use of neurotrophic factors to enhance the speed and quality of axon growth. Clinical studies will be necessary to determine the benefit of these strategies.

Dorsal Approach for Management of Proximal Interphalangeal Joint Flexion Contracture.

Proximal interphalangeal (PIP) joint contracture is a common, difficult clinical problem that can arise from minor trauma. Management is difficult because outcomes are unpredictable and often poor, due to residual flexion deformities postoperatively. The dorsal approach for flexion contracture of the PIP joint is not discussed in present literature. In this technique guide, we wish to describe and explain the rationale for a dorsal approach. In our experience, a dorsal approach allows for ease of access to all pathologic structures, with simple positioning of the digit to allow access to volar structures, as well as when addressing more than one digits with a PIP contracture. Finally, similar to the midaxial approach, the dorsal approach also eliminates any volar soft tissue concerns and need for supplemental coverage.

A Logistic Regression Analysis of Factors Associated with Guarded Outcome after Carpal Tunnel Release in Symptomatic Carpal Tunnel Syndrome.

BACKGROUND: The Boston Carpal Tunnel Questionnaire (BCTQ) is a validated measurement tool to assess the severity of carpal tunnel syndrome, and improvements in the BCTQ after carpal tunnel release (CTR) have been demonstrated to influence patient satisfaction. The authors hypothesized that patient-related factors influence response in BCTQ subscales, including the Symptom Severity Scale and the Functional Status Scale, after CTR. METHODS: Patients who underwent surgery with follow-up BCTQ were identified from a prospectively maintained database. Paired t tests were used to compare BCTQ subscales at each follow-up time point. Minimal clinically important differences were set. Patients below these thresholds were deemed as having failure to improve after CTR. Univariate analysis was used to identify risk factors for failure to improve after CTR. Multivariate logistic regression was used to identify independent predictors for failure to improve after CTR. RESULTS: A total of 106 patients met inclusion criteria. Patients demonstrated significant improvements at all follow-up time points. The factor most associated with improvement beyond the minimal clinically important differences was a more severe score in the respective domain assessed. Other independent factors that influenced outcome after CTR included race, concomitant cubital tunnel release, sex, and age. CONCLUSIONS: CTR results in significant improvements in BCTQ and its subscales, with improvements stabilizing after 6 weeks. In a select cohort of patients, failure to improve after CTR occurs with factors independently associated with a lower degree of improvement. Identification of patients with these risk factors will provide a basis for counseling and increased monitoring of patients at risk for a guarded prognosis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Comparison of Fusion Rates/Complications Between Different Types of Thumb Metacarpophalangeal Fusion Techniques.

BACKGROUND: Thumb metacarpophalangeal (MP) fusion is generally successful; however, complications have been reported to occur in 0% to 30% of cases, whereas nonunion rates vary by method but, overall, are reported to occur in 0% to 15% of cases. Many fixation techniques have been described, but there is no consensus on the optimal fusion technique. Our goal was to compare complication and union rates of different thumb MP arthrodesis techniques. METHODS: We performed a retrospective review of patients who underwent primary thumb MP fusion between 2000 and 2022. Patients who underwent revision fusion, fusion for infection, or amputation were excluded. Fusions of MP joints of other fingers were also excluded. Data collection consisted of demographic data, complications, time to fusion, rate of delayed union and rate of nonunion. Five different fusion constructs were evaluated during our study period: staples, Kirschner wires (K-wires), cerclage, K-wires with cerclage, and intramedullary screw. RESULTS: Forty-seven patients underwent fusion with staples, 16 with K-wires, 14 with cerclage, 9 with K-wires and cerclage, and 6 with an intramedullary screw. The individual complication and nonunion rates differed significantly among the groups with the intramedullary screw group having a statistically higher rate of nonunion (P = .004). Furthermore, smoking, diabetes, and being overweight were associated with nonunions. CONCLUSION: Union rates were significantly lower in patients treated with an intramedullary screw and those who are smokers, diabetics, and/or overweight. Caution should be exercised when using intramedullary screw fixation for MP fusion, especially in patients with these comorbidities.

Upper-extremity transplantation using a cell-based protocol to minimize immunosuppression.

OBJECTIVE: To minimize maintenance immunosuppression in upper-extremity transplantation to favor the risk-benefit balance of this procedure. BACKGROUND: Despite favorable outcomes, broad clinical application of reconstructive transplantation is limited by the risks and side effects of multidrug immunosuppression. We present our experience with upper-extremity transplantation under a novel, donor bone marrow (BM) cell-based treatment protocol ("Pittsburgh protocol"). METHODS: Between March 2009 and September 2010, 5 patients received a bilateral hand (n = 2), a bilateral hand/forearm (n = 1), or a unilateral (n = 2) hand transplant. Patients were treated with alemtuzumab and methylprednisolone for induction, followed by tacrolimus monotherapy. On day 14, patients received an infusion of donor BM cells isolated from 9 vertebral bodies. Comprehensive follow-up included functional evaluation, imaging, and immunomonitoring. RESULTS: All patients are maintained on tacrolimus monotherapy with trough levels ranging between 4 and 12 ng/mL. Skin rejections were infrequent and reversible. Patients demonstrated sustained improvements in motor function and sensory return correlating with time after transplantation and level of amputation. Side effects included transient increase in serum creatinine, hyperglycemia managed with oral hypoglycemics, minor wound infection, and hyperuricemia but no infections. Immunomonitoring revealed transient moderate levels of donor-specific antibodies, adequate immunocompetence, and no peripheral blood chimerism. Imaging demonstrated patent vessels with only mild luminal narrowing/occlusion in 1 case. Protocol skin biopsies showed absent or minimal perivascular cellular infiltrates. CONCLUSIONS: Our data suggest that this BM cell-based treatment protocol is safe, is well tolerated, and allows upper-extremity transplantation using low-dose tacrolimus monotherapy.

The carpal insertions of the transverse carpal ligament.

PURPOSE: To quantitatively define the anatomic insertions of the transverse carpal ligament (TCL) to the carpals. METHODS: We dissected 5 fresh-frozen cadaver limbs, isolating the TCL. The ligament insertion sites into bone were clearly marked and photographed. We then used computer software to measure the area of insertion into the individual carpals. RESULTS: The TCL had consistent insertion sites into the scaphoid, trapezium, pisiform, and hamate. The average insertion of the TCL on the scaphoid was 6 × 6 mm (proximal to distal × radial to ulnar maximum distance), trapezium 13 × 6 mm, pisiform 9 × 6 mm, and hamate 11 × 5 mm. The area of ligament insertion on the scaphoid was 29 mm(2), trapezium was 42 mm(2), pisiform was 38 mm(2), and hamate was 40 mm(2). The perimeter of the ligament insertion on the scaphoid was 21 mm, trapezium was 28 mm, pisiform was 25 mm, and hamate was 29 mm. CONCLUSIONS: The TCL has a broad but definable footprint on the trapezium and scaphoid on the radial side and the hamate and the pisiform on the ulnar side of the carpal tunnel. The distal carpal insertion sites are longer and oblong, whereas the proximal insertion sites are more circular. CLINICAL RELEVANCE: Precise knowledge of TCL attachment sites may allow the surgeon greater confidence and safety during procedures that involve its release, such as carpal tunnel release, trapeziectomy, hook of hamate excision, or Guyon canal release.

Effect of Capitolunate Positioning on Outcomes in Scaphoid Excision and 4-Bone Fusion Patients.

BACKGROUND: Scaphoid excision and 4-bone fusion (4BF) is a surgical procedure to treat scapholunate advanced collapse. Some surgeons align the lunate over the capitates, whereas others leave the capitate in its uncovered native position. The capitolunate angle may affect long-term outcomes. This study examined whether postsurgical outcomes differed based on these differences in positioning. METHODS: A retrospective analysis was performed for patients that underwent a 4BF between 2006 and 2020. Wrist range of motion; pain (0-10); and Disabilities of the Arm, Shoulder, and Hand (DASH) scores were recorded. The width of the capitate, the width of the lunate contacting the capitate, and the capitolunate angle were measured. Pearson correlations and t tests were performed. For t tests of capitolunate uncovering, patients were divided into 2 groups: patients with 0% capitate uncovering and patients with >0% uncovering. For capitolunate angle, the 2 groups were patients with a capitolunate angle of ≤10° and patients with a capitolunate angle of >10°. RESULTS: There was a significant correlation between capitate coverage and wrist extension, but no correlation for flexion, pain, or DASH scores. Group 1 (0% uncovering) had increased wrist extension and decreased pain compared with group 2 (>0% uncovering). There were no significant correlations or differences in the analyses of capitolunate angle's impact on outcomes. CONCLUSIONS: In patients undergoing 4BF, those who had the lunate aligned to completely cover the capitate head had improved wrist extension and pain compared with patients where the capitate head was left partially uncovered. Capitolunate angle was not predictive of postsurgical outcomes.

Comparison of Patient-Reported Outcomes With or Without Prophylactic Carpal Tunnel Release After Distal Radius Fracture Stabilization.

Distal radius fractures (DRFs) are frequently complicated by acute carpal tunnel syndrome (CTS), which, if unrecognized, can cause permanent median neuropathy. Some surgeons recommend "prophylactic" carpal tunnel release (CTR) during open reduction and internal fixation (ORIF) of DRF. Patient-reported outcomes (PROs) and safety data regarding prophylactic vs symptomatic CTR strategies during DRF fixation are lacking. We conducted a retrospective review of two management strategies for DRFs at our institution (2017 to 2019). Group 1 consisted of patients operated on by two surgeons performing ORIF and symptomatic CTR only for acute CTS. Group 2 consisted of patients operated on by a third surgeon performing ORIF and prophylactic CTR on all patients irrespective of median nerve symptoms. The PROs included QuickDASH Wrist and PROMIS physical/mental health preoperatively vs at final follow-up. Demographic information, complications, and return to the operating room were recorded. Group 1 (36 patients) and group 2 (76 patients) were demographically similar. The mechanism of injury was more severe in group 1 (P<.05), but preoperative PROs were similar between the two groups. Eight patients (22.2%) in group 1 had symptomatic CTR for acute CTS. Significant improvement occurred within both groups from preoperative to final follow-up for PROMIS physical function and QuickDASH Wrist scores (P<.05). Intergroup PROs were not significantly different at either time point. One patient in group 1 (2.8%) and 2 patients in group 2 (2.6%) returned to the operating room due to median nerve symptoms (P>.05). A prophylactic CTR strategy is not associated with improved PROs compared with a symptomatic strategy during ORIF of DRF. [Orthopedics. 2023;46(6):e362-e368.].

Epiphyseal osteochondromas of the upper limb: a report of 7 cases.

BACKGROUND: Originally described as osteochondromatous lesions arising from the tarsal bones, osteochondromas arising from the epiphysis or carpal/tarsal bones are less common than those arising from the metaphysis. Histologically, all osteochondromas are indistinguishable regardless of the location from which they arise. Few case reports and case series exist describing these lesions in the upper limb. METHODS: We review 7 cases of osteochondromas arising from epiphyses and ossicles in the upper limb treated at 3 institutions. Patients were followed for an average of 5.7 years. The average patient age at the presentation was 7.8 years. RESULTS: We identified 25 lesions: 5 distal radial epiphyseal, 3 distal radial metaphyseal, 4 scaphoid, 4 lunate, 4 trapezial, 2 accessory ossicles adjacent to the trapezium, 2 trapezoid, and 1 metacarpal lesion. Three patients presented with pain, 5 with decreased motion, and 3 with angular deformity. In 1 case, the lesion presented as an incidental finding. Four patients underwent a total of 7 procedures: 2 open biopsies, 2 distal radial epiphyseal lesion excisions, 2 revisions, and 1 excision of all lesions with a scaphoid osteotomy. CONCLUSIONS: Intra-articular and transosseous lesions are more likely to result in angular deformities and loss of motion at the joints, whereas juxtaphyseal and transphyseal lesions are more likely to result in growth disturbances and angular deformities at the physis. LEVEL OF EVIDENCE: Case series, level IV.

Technical aspects of the recipient operation in hand transplantation.

The goal of hand allotransplantation is to achieve graft survival and useful long-term function. To achieve these goals, precise surgical technique is of critical importance. The key surgical steps and sequence of events in hand allotransplantation are similar to major upper extremity replantations, but are modified to accommodate major conceptual differences that exist between the two procedures.

Accuracy of Surgeon Diagnosis in Predicting Carpal Tunnel Syndrome.

Background: The utility of electrodiagnostic studies (EDX) continues to be a point of debate in the diagnosis of carpal tunnel syndrome (CTS). If surgeons can predict the results of EDX with high accuracy, it may suggest that ordering the test is unnecessary from a diagnostic standpoint. Methods: Two surgeons with subspecialty training in hand surgery were asked to classify hands into "definitely having or not having CTS" or into an "unclear category" when presented with patients having a chief complaint of hand paresthesias. Clinical diagnosis was compared against EDX, ordered after the initial patient visit, as the reference standard. Results: Of the 175 hands, 111 hands were predicted to have CTS, 37 hands were predicted not to have CTS, and 27 hands had an unclear diagnosis. Overall surgeon accuracy was 86% (124/148). Accuracy was improved when subdivided by a positive prediction of CTS (88%) compared with a negative prediction of CTS (70%) (P = .03). Sensitivity was 90% and specificity was 67%. The senior surgeon had a higher accuracy at 90% than the more junior surgeon at 74% (P = .02). Conclusions: Surgeons with sub-specialty training in hand surgery are able to accurately diagnose CTS without EDX. Surgeon experience is important and resulted in a higher accuracy in predicting EDX results.

Surgical treatment of pediatric posttraumatic palmar midcarpal instability: case report.

We treated a 6-year-old child able to extend her wrist only to within 30 degrees of the neutral position secondary to posttraumatic palmar midcarpal instability with palmar and dorsal capsulodesis and pinning. More than 8 years after surgery, she has no complaints referable to her wrist and has 30 degrees of active wrist extension. Although unpredictable in adults, soft-tissue reconstruction is a treatment option in the pediatric patient with posttraumatic palmar midcarpal instability.

Osteoarthritis of the distal interphalangeal joint.

Osteoarthritis occurs with the highest prevalence in the distal interphalangeal joint of the hand and has been divided into an erosive and a nonerosive form. The pathogenesis of the early stages of osteoarthritis is poorly understood, but considerable emphasis has been placed on the role of cartilage and subchondral bone as well as soft tissue structures such as collateral ligaments and tendons. Radiographic evaluation represents the most standardized method to quantify disease progression, with different systems having been developed for defining and grading radiographic features. This current concepts article examines the recent knowledge base regarding the etiology, pathogenesis, and evaluation of osteoarthritis of the distal interphalangeal joint.