Molecular diagnosis, clinical evaluation and phenotypic spectrum of Townes-Brocks syndrome: insights from a large Chinese hearing loss cohort.

BACKGROUND: Townes-Brocks syndrome (TBS) is a rare genetic disorder characterised by multiple malformations. Due to its phenotypic heterogeneity and rarity, diagnosis and recognition of TBS can be challenging and there has been a lack of investigation of patients with atypical TBS in large cohorts and delineation of their phenotypic characteristics. METHODS: We screened SALL1 and DACT1 variants using next-generation sequencing in the China Deafness Genetics Consortium (CDGC) cohort enrolling 20 666 unrelated hearing loss (HL) cases. Comprehensive clinical evaluations were conducted on seven members from a three-generation TBS family. Combining data from previously reported cases, we also provided a landscape of phenotypes and genotypes of patients with TBS. RESULTS: We identified five novel and two reported pathogenic/likely pathogenic (P/LP) SALL1 variants from seven families. Audiological features in patients differed in severity and binaural asymmetry. Moreover, previously undocumented malformations in the middle and inner ear were detected in one patient. By comprehensive clinical evaluations, we further provide evidence for the causal relationship between SALL1 variation and certain endocrine abnormalities. Penetrance analysis within familial contexts revealed incomplete penetrance among first-generation patients with TBS and a higher disease burden among their affected offspring. CONCLUSION: This study presents the first insight of genetic screening for patients with TBS in a large HL cohort. We broadened the phenotypic-genotypic spectrum of TBS and our results supported an underestimated prevalence of TBS. Due to the rarity and phenotypic heterogeneity of rare diseases, broader spectrum molecular tests, especially whole genome sequencing, can improve the situation of underdiagnosis and provide effective recommendations for clinical management.

Osteoblastoma of the thumb with a novel PRSS44::ALK fusion and literature review of osteoblastoma of hands and feet bones.

Osteoblastomas (OBs) are benign neoplasms constituting approximately 1% of primary bone tumors with a predilection for the spine and sacrum. We describe an OB of the proximal phalanx of the left thumb in a 38-year-old female. MRI of left hand demonstrated a 29-mm mildly expansile enhancing lesion involving the entire proximal phalanx of the first digit. Histology displayed a bone-forming tumor consisting of trabeculae of remodeled woven bone framed by plump osteoblasts in a vascularized background. Next-generation sequencing analysis identified a PRSS44::ALK fusion gene.

Distribution of nerve endings in human thumb interphalangeal joint.

This study aims to quantitatively analyze the distribution of encapsulated nerve endings in the human thumb interphalangeal (IP) joint capsule. There are three types of nerve endings. Type-I nerve endings (Ruffini-like ending) sense pressure changes, Type II (Pacini-like ending) nerve endings contribute to the kinesthetic sense, and Type III (Golgi-like ending) nerve ending provides proprioceptive information. We dissected five right thumbs IP joints from freshly frozen cadavers (5 men). The mean age of the cadavers at the time of death was 63.4 years (55-73). Sections were stained with the hematoxylin-eosin and antiprotein gene product 9.5 (PGP9.5) to identify encapsulated nerve endings. Transverse sections were cut and divided into volar, dorsal, and then into two equal parts, proximal and distal. The density of encapsulated nerve endings compared to volar versus dorsal and proximal versus distal regions was examined. This study showed that type 1 nerve endings were more common in the distal parts of the IP joint (p < 0.05). Also, type 3 nerve endings were observed in the thumb IP joint. There was no difference between regions in type II and type III nerve endings. The current study demonstrates that the distribution of encapsulated nerve endings in the IP joint is different from the PIP and DIP joints. Moreover, further studies are required to understand the thumb's physiology.

Nail-patella syndrome with nephropathy in a de novo LMX1B mutation: triangular lunula of the thumb and lack of finger creases as clues.

Nail-patella syndrome (NPS) is an autosomal dominant disease caused mostly by mutations in the LMX1B gene and is characterized by hypoplastic nails, hypoplastic patella, elbow deformities, glaucoma, and nephropathy, sometimes leading to kidney failure. The combination and the severity of symptoms vary greatly from patient to patient. Because a kidney biopsy may show nonspecific findings, patients with nephropathy alone may not be diagnosed without undergoing genetic testing. We examined the case of a 6-year-old girl with persistent high proteinuria who was not diagnosed by kidney biopsy but had a diagnosis of a de novo mutation in the LMX1B gene following genetic testing. Retrospectively, only the thumbs showed triangular lunulae, while the third and fourth fingers lacked skin creases over the distal interphalangeal joints, which is subtle but characteristic of NPS. Notifying pediatric nephrologists of these findings can help avoid unnecessary kidney biopsies and lead to early detection of the disease.

Surgical Reconstruction of Type IV Hypoplasia of the Thumb (Floating Thumb) in Infants: A Retrospective Analysis of Functional Outcomes and Radiographic Alignment.

BACKGROUND Congenital hypoplasia of the thumb type IV, also known as floating thumb, is a condition in which 2 small phalanges are attached to the hand with a thin skin bridge. Surgical management options for this condition vary from amputation to flap reconstruction. MATERIAL AND METHODS This retrospective study analyzed 11 infants with congenital hypoplasia of the thumb type IV who underwent surgical reconstruction using a modified vascularized polydactylous hallux flap. The study included 6 male and 5 female infants, aged 6 to 24 months. Functional evaluations and radiographic studies were conducted postoperatively. RESULTS All 11 patients underwent the complete surgical protocol. Successful vascular and nerve anastomoses were performed during the initial procedure, ensuring sufficient blood supply and neural connectivity to the transferred toes. The second operation showed promising outcomes, including improvements in thumb opposition, grasp strength, and overall function. Postoperative assessments demonstrated satisfactory radiographic alignment and no major complications during the follow-up period. CONCLUSIONS The modified vascularized polydactylous hallux flap reconstruction is a viable surgical option for managing congenital hypoplasia of the thumb type IV in infants. This technique effectively restores thumb opposition, grasp strength, and overall hand function, with satisfactory radiographic alignment and minimal complications. The study findings support the efficacy and safety of this surgical approach in addressing this rare congenital anomaly.

Different Thumb Positions in the Tetraplegic Hand.

OBJECTIVE: To analyze factors associated with malposition that affects function of the thumb in individuals with tetraplegia. DESIGN: Retrospective cross-sectional study. SETTING: Rehabilitation Center for Spinal Cord Injury. PARTICIPANTS: Anonymized data from 82 individuals (68 men), mean age 52.9±20.2 (SD) with acute/subacute cervical spinal cord injury C2-C8 AIS A-D recorded during 2018-2020. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Motor point (MP) mapping and manual muscle test (MRC) of 3 extrinsic thumb muscles (flexor pollicis longus (FPL), extensor pollicis longus (EPL), and abductor pollicis longus (APL)). RESULTS: 159 hands in 82 patients with tetraplegia C2-C8 AIS A-D were analyzed and assigned to "key pinch" (40.3%), "slack thumb" (26.4%), and "thumb-in-palm" (7.5%) positions. There was a significant (P<.0001) difference between the 3 thumb positions depicted in lower motor neuron (LMN) integrity tested by MP mapping and muscle strength of the 3 muscles examined. All studied muscles showed a significantly different expression of MP and the MRC values (P<.0001) between the "slack thumb" and "key pinch" position. MRC of FPL was significantly greater in the group "thumb-in-palm" compared with "key pinch" position (P<.0001). CONCLUSIONS: Malposition of the thumb due to tetraplegia seems to be related to the integrity of LMN and voluntary muscle activity of the extrinsic thumb muscles. Assessments such as MP mapping and MRC of the 3 thumb muscles enable the identification of potential risk factors for the development of thumb malposition in individuals with tetraplegia.

A novel heterozygous variant of the SALL1 gene with atypical Townes-Brocks syndrome phenotypes in Chinese family.

Townes-Brocks syndrome (TBS) is an autosomal dominant disorder characterised by the triad of anorectal, thumb, and ear malformations. It may also be accompanied by defects in kidney, heart, eyes, hearing, and feet. TBS has been demonstrated to result from heterozygous variants in the SALL1 gene, which encodes zinc finger protein believed to function as a transcriptional repressor. The clinical characteristics of an atypical TBS phenotype patient from a Chinese family are described, with predominant manifestations including external ear dysplasia, unilateral renal hypoplasia with mild renal dysfunction, and hearing impairment. A novel heterozygous variant c.3060T>A (p.Tyr1020*) in exon 2 of the SALL1 gene was identified in this proband. Pyrosequencing of the complementary DNA of the proband revealed that the variant transcript accounted for 48% of the total transcripts in peripheral leukocytes, indicating that this variant transcript has not undergone nonsense-mediated mRNA decay. This variant c.3060T > A is located at the terminal end of exon 2, proximal to the 3' end of the SALL1 gene, and exerts a relatively minor impact on protein function. We suggest that the atypical TBS phenotype observed in the proband may be attributed to the truncated protein retaining partial SALL1 function.

A novel CPR-assist device vs. established chest compression techniques in infant CPR: A manikin study.

INTRODUCTION: Guidelines for infant CPR recommend the two-thumb encircling hands technique (TTT) and the two-finger technique (TFT) for chest compression. Some devices have been designed to assist with infant CPR, but are often not readily available. Syringe plungers may serve as an alternative infant CPR assist device given their availability in most hospitals. In this study, we aimed to determine whether CPR using a syringe plunger could improve CPR quality measurements on the Resusci-Baby manikin compared with traditional methods of infant CPR. METHODS: Compression area with a diameter of 1 to 2 cm is recommended in previous infant CPR device researches. In this is a randomized crossover manikin study, we examined the efficacy of the Syringe Plunger Technique (SPT) which uses the plunger of the 20 ml syringe with a 2 cm diameter flat piston, commonly available in hospital, for infant External Chest Compressions (ECC). Participants performed TTT, TFT and SPT ECC on Resusci® Baby QCPR® according to 2020 BLS guidelines. RESULTS: Sixty healthcare providers participated in this project. The median (IQR) ECC depths in the TTT, TFT and SPT in the first minute were 41 mm (40-42), 40 mm (38-41) and 40 mm (39-41), respectively, with p < 0.001. The median (IQR) ECC recoil in the TTT, TFT and SPT groups in the first minute was 15% (1-93), 64% (18-96) and 53% (8-95), respectively, with p = 0.003. The result in the second minute had similar findings. The SPT had the best QCPR score and less fatigue. CONCLUSION: The performance of chest compression depth and re-rebound ratio was statistically different among the three groups. TTT has good ECC depth and depth accuracy but poor recoil. TFT is the complete opposite. SPT can achieve a depth close to TTT and has a good recoil performance as TFT. Regarding comprehensive performance, SPT obtains the highest QCPR score, and SPT is also less fatigued. SPT may be an effective alternative technique for infant CPR.

Anti-cancer therapeutic agents and carpal tunnel syndrome: Clinical, electrodiagnostic, and ultrasound findings in seven patients.

INTRODUCTION: Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy and rarely develops after drug therapy. This study describes the clinical, electrodiagnostic (EDX), and ultrasound (US) findings in seven patients who experienced CTS due to anti-cancer therapeutic agents. METHODS: All patients underwent EDX testing, and four patients had an US study. RESULTS: CTS occurred in four patients with aromatase inhibitors, two with immune checkpoint inhibitors, and one with a selective estrogen receptor modulator. The mean duration between initiation of the anti-cancer therapeutic agents and symptom onset was 6 weeks (range: 2-12 weeks). Decreased digit sensation was noted in all patients; wasting and weakness of the abductor pollicis brevis (APB) was observed in three (42.8%) patients. The compound muscle action potentials (CMAP) of the APB and sensory nerve action potentials of the second or third digit could not be recorded in two (28.5%) and four (57.1%) patients, respectively. The needle EMG detected fibrillations and positive sharp waves in the APB in two patients. The motor unit potentials of the APB were decreased with large polyphasics in three (42.8%) patients. Of the four patients who underwent US testing, all had increased cross-sectional area of the median nerve at the carpal tunnel inlet, three (75%) had thenar muscle atrophy, and two (50%) had a loss of fascicular pattern. Three (42.8%) patients underwent a CTR. CONCLUSIONS: Physicians should be cognizant of the relationship between anti-cancer therapeutic agents and CTS. EDX studies and US play important roles in the diagnostic assessment of such patients.

The Female Thumb Carpometacarpal Joint: Motion and Force Changes Due to Arthritis and Surgical Intervention.

Thumb carpometacarpal (CMC) osteoarthritis (OA) has been one of the most common locations of hand OA. CMC OA disproportionately occurs in females over males. In severe cases, surgical intervention may be needed. However, to determine the effects of surgical treatment, normative, pre-, and postsurgery function must be understood. The goals of this work were to compare the thumb motion and force abilities of older healthy (OH) females without CMC OA to those of females with CMC OA and who received ligament reconstruction with tendon interposition (LRTI) surgery at time points presurgery, 3- and 6-months postsurgery. On average, CMC OA participants 3- and 6-months postsurgery showed 35.6% and 32.9% less overall metacarpal motion compared to presurgery, 31.9% and 29.1% less than OH, and exhibited altered motion. Metacarpal flexion/extension and abduction/adduction ranges were 51.9 deg and 43.4 deg for OH, 52.9 deg and 40.3 deg presurgery, 39.9 deg and 33.5 deg at 3-months, and 42.6 deg and 32.7 deg at 6-months postsurgery. On average, participants had increased force generation at 6-months postsurgery compared to presurgery, and 20% of participants returned to the level of OH females. These data sets highlight changes in thumb metacarpal movement and thumb force generation due to disease and surgical intervention. This work has the ability to support both surgeons and patients through improved outcome assessments as well as additional data to inform the decision process on intervention.

Kinematic Investigation of Healthy, Arthritic, and Postsurgery Thumbs: Is the Metacarpophalangeal Joint the Gateway to Carpometacarpal Arthritis?

The thumb carpometacarpal (CMC) joint is one of the most likely joints to develop osteoarthritis (OA). If conservative treatments fail to alleviate symptoms, surgery may be pursued. Kinematic outcomes of CMC surgery techniques have been described, but current tools have limitations in capturing motion abilities. The goals of this study were (1) develop a new and robust set of kinematic outcome measures, and apply them to (2) a cohort of younger and older control individuals without CMC OA to determine age and sex-related changes, and (3) a cohort of participants with CMC OA before, 3 months, and 6 months after undergoing thumb ligament reconstruction with tendon interposition surgery to detect the impacts of surgery. 52 (26 males, 26 females) control and 18 (3 males, 15 females) surgical participants were tested. Kinematics were investigated using motion capture by mapping the three-dimensional motion space of the whole thumb, and two-dimensional motion boundaries of the metacarpal (MC) and proximal phalange (PP). Visual analog pain score was recorded. Older control participants had shifted regions of motion compared to younger participants (p ≤ 0.027), suggesting asymptomatic CMC wear. Control females had 31% more metacarpophalangeal (MCP) motion than control males (p = 0.013), which could alter loading paths through the CMC joint and increase OA risk. Pain at 6 months postsurgery was 72% less than presurgery (p < 0.001), but motion abilities were 20-28% less than presurgery (p ≤ 0.074) and 24-40% less than control participants (p ≤ 0.066). These techniques have the possibility of identifying presymptomatic motion changes, including those at the metacarpophalangeal joint in CMC OA progression.

Effective shape of ball-and-socket prosthesis in restoring range of thumb motion for total thumb carpometacarpal joint arthroplasty: three-dimensional motion analysis.

PURPOSE: Total joint arthroplasty (TJA) has often been used to treat thumb carpometacarpal (CMC) osteoarthritis (OA). However, guidelines for the CMC prosthesis shape remain unclear. This study aimed to identify the effective shape of a ball-and-socket prosthesis in restoring the range of thumb motion after TJA. METHODS: The participants were 10 healthy young adult men (22-32 years; 26.8 ± 3.57 [mean ± SD]). CT scans were performed in eight static limb positions during abduction and flexion. We defined three design variables (offset R, height H, and neck rotation angle Φ) as the variables that determine the basic shape of the ball-and-socket prosthesis. The ideal values of these design variables were examined based on the results of a 3D motion analysis, which evaluated the change in the posture of the first metacarpal (r, h, and φ corresponding to R, H, and Φ, respectively) relative to the center of rotation (COR) during abduction and flexion. We also simulated the effect of these design variables on the range of thumb motion after TJA using 3D CAD. RESULTS: We found that the values of r and h averaged over all limb positions were 6.92 ± 1.60 mm and 51.02 ± 1.67 mm, respectively, showing that these values remained constant regardless of limb position. In contrast, φ changed significantly. The simulation results indicated that Φ affected the range of thumb motion after TJA, and Φ = 0° relatively reproduced all limb positions compared to other values. CONCLUSION: Our results suggested that the desirable values of R and H were the average of r and h over several limb positions and that Φ = 0° was effective in restoring the range of thumb motion after TJA. Our results will provide surgeons with new guidelines for selecting a prosthesis.

HES1 is a novel downstream modifier of the SHH-GLI3 Axis in the development of preaxial polydactyly.

Sonic Hedgehog/GLI3 signaling is critical in regulating digit number, such that Gli3-deficiency results in polydactyly and Shh-deficiency leads to digit number reductions. SHH/GLI3 signaling regulates cell cycle factors controlling mesenchymal cell proliferation, while simultaneously regulating Grem1 to coordinate BMP-induced chondrogenesis. SHH/GLI3 signaling also coordinates the expression of additional genes, however their importance in digit formation remain unknown. Utilizing genetic and molecular approaches, we identified HES1 as a downstream modifier of the SHH/GLI signaling axis capable of inducing preaxial polydactyly (PPD), required for Gli3-deficient PPD, and capable of overcoming digit number constraints of Shh-deficiency. Our data indicate that HES1, a direct SHH/GLI signaling target, induces mesenchymal cell proliferation via suppression of Cdkn1b, while inhibiting chondrogenic genes and the anterior autopod boundary regulator, Pax9. These findings establish HES1 as a critical downstream effector of SHH/GLI3 signaling in the development of PPD.

Mid- and long-term clinical results of the Elektra and Moovis prosthesis for trapeziometacarpal joint replacement.

BACKGROUND: Total joint arthroplasty as a surgical treatment option for trapeziometacarpal joint arthritis is recently revived. The aim of this study is to report on mid- and long-term results of the Elektra (single-mobility) and Moovis (dual-mobility) prosthesis for treatment of primary thumb carpometacarpal joint arthritis. METHODS: In this retrospective, monocentric, descriptive cohort study, 31 prostheses were evaluated that were implanted by a single surgeon in 26 patients between 2009 and 2019. Indication for surgery was trapeziometacarpal joint osteoarthritis (Eaton/Littler Stage II and III). Clinical and radiological follow-up was performed at a minimum of 24 months. The postoperative assessment included range of motion, pain, strength as well as functional scores (DASH, MHQ). Implant survival and complications were the primary endpoints. RESULTS: 10 Elektra and 21 Moovis prostheses were implanted between 2009 and 2019 with a mean follow-up of 74.2 months in the Elektra and 41.4 months in the Moovis group. The average patients' age at surgery was 64 years. Postoperative pain levels (VAS 0-10) were below 2 at rest and under stress in both groups. Grip/pinch strength and range of motion showed results comparable to the contralateral hand. Opposition was excellent with an average Kapandji index of 9.6 in both groups. Elektra achieved slightly better functional scores in the DASH and MHQ score. Satisfaction was high in both groups, and 96% of the patients would recommend the procedure. Metacarpophalangeal hyperextension > 15° was seen in 3 patients per group preoperatively and was corrected to < 5° post-surgery. 3 Elektra prostheses were revised due to cup loosening and dislocation for cup and/or neck replacement or secondary trapeziectomy. 1 Moovis prosthesis was revised with an exchange of the neck to a larger size due to restricted movement. After the mean follow-up of 7.9 years in Elektra and 3.5 years in MOOVIS, cumulative survival was 68.6% vs. 95.2%, respectively. CONCLUSIONS: In this mid- to long-term retrospective analysis, total joint arthroplasty in primary trapeziometacarpal joint arthritis results in low pain levels, excellent mobility and clinical function. Patient satisfaction is overall high. While revision due to cup loosening occurred more often in patients with single-mobility implants, no cases of dislocation or loosening of components were observed in the dual-mobility group. TRIAL REGISTRATION: The study was conducted in accordance with the Declaration of Helsinki, and approved by the Ethics Committee of the Medical Faculty of Heidelberg University, reference number S-150/2020.

Arthrodesis of distal interphalangeal and thumb interphalangeal joint: a retrospective cohort study of 149 cases.

BACKGROUND: Arthrodesis of finger joints is often the last line of treatment of severe pain due to osteoarthritis, rheumatoid arthritis, or mallet finger. At the Department of Orthopedic and Hand Surgery, Örebro University Hospital (ÖUH) in Sweden, the Kirschner-wire technique was standard until 2020, when the headless compression screw technique was introduced as a complement. There is no consensus on which method is superior. The purpose of this study was to examine the outcomes and complications associated with distal interphalangeal (DIP) joint and thumb interphalangeal (IP) joint arthrodesis, and to see whether these correlated with patient-dependent and treatment-related factors. METHODS: In a retrospective cohort study, we evaluated a total of 149 consecutive arthrodeses (118 DIP joint and 31 thumb IP joint) performed between 2012 and 2022. The primary outcome was risk factors for complications after arthrodesis. RESULTS: Osteoarthritis was the most common indication (56%) for arthrodesis. The majority of the patients were females (74%), and the median age was 62 (range 18-86). The complication frequency was 35%, with infection being the most common (25%). Time to completed follow up was < 12 weeks in the majority of the cases (58%). There were no significant differences in complication rate between the 136 joints operated using Kirschner wire and the 13 joints operated using headless compression screws. There was no significant increased risk of complications among smokers or patients with rheumatoid arthritis. Diabetes and surgeon experience had a significant influence on the risk of complication (p = 0.036 and p = 0.006, respectively). CONCLUSIONS: Osteoarthritis was the most common indication for arthrodesis and postoperative complications occurred at a rate similar to that reported in the existing literature. Diabetes and surgeon experience were identified as factors increasing the risk of postoperative complications in these DIP/thumb IP joint arthrodeses. However, there was no significant difference between the two techniques (Kirschner wire and headless compression screws) regarding complications. Further studies are needed in order to determine the optimal type of operation and choice of implant. TRIAL REGISTRATION: Researchweb CRIS #280,998, 26th of July 2023.

MRI spectrum of injuries to the thumb metacarpophalangeal joint ulnar collateral ligament with a proposed expanded classification of injuries in American football players.

Injuries to the ulnar collateral ligament of the thumb metacarpophalangeal joint are of both historic and modern interest for athletes and non-athletes alike. The thumb metacarpophalangeal joint requires stability in both flexion and extension utilizing a combination of static and dynamic stabilizers. This article reviews the magnetic resonance imaging categorization of thumb ulnar collateral ligament injuries and proposes two additional injury patterns seen in high-level and professional athletes who play American football. In addition to the direct magnetic resonance imaging findings in collateral ligament tears, secondary findings of rotation and subluxation can be seen at the thumb metacarpophalangeal joint due to the altered physiologic forces on the joint. Internal brace augmentation via suture tape of a traditional ulnar collateral ligament repair is a novel surgical technique that provides protection during initial healing and the ensuing remodeling phase following repair or reconstruction, resulting in a faster return to play.

High Fracture Rate of AVANTA Silicone Implant Following Arthroplasty of the Thumb MCP Joint of Rheumatoid Arthritis Patients with Boutonniere Deformities.

We retrospectively investigated the mid-term outcomes of arthroplasty using the AVANTA silicone implant for thumb metacarpophalangeal (MCP) joints with boutonniere deformity in patients with rheumatoid arthritis (RA). This study involved 36 thumbs of 33 RA patients with a mean follow-up period of 5.1 years (range, 2.0-13.3). Postoperatively, the mean extension was significantly increased and the mean flexion was significantly decreased (p<0.001, p<0.001, respectively), resulting in the mean arc of range of motion (ROM) shifting in the direction of extension after surgery. Implant fracture was observed in 10 thumbs (28%), and 4 of these (11%) underwent revision surgery. The survivorship with implant fracture and revision surgery as endpoints were 73.4% and 91.8% at 5 years, respectively. The preoperative arc of ROM and the postoperative flexion range of the implant-fracture group were significantly greater than those in the no-implant-fracture group (p=0.039, 0.034, respectively). These results suggest the importance of patient education and careful rehabilitation to prevent excessive flexion. Overall, the AVANTA silicone implant showed a relatively high rate of implant fracture at our institute.

Conjoined Free Fibula Transplantation and First Carpometacarpal Joint Prosthesis for Functional Thumb Reconstruction-A Case Report.

BACKGROUND: Giant cell tumors grow locally invasive with osseous and soft tissue destruction, requiring wide resection to avoid recurrence. Stable reconstruction of the first carpometacarpal (CMC-1) joint remains a challenge due to its high range of mobility. The latter is of paramount for the functionality of the hand. PURPOSE: Therefore, the aim of this study was to report our approach for a combined reconstruction of the first metacarpal and the CMC-1 joint. METHODS: A 58-year-old woman underwent wide resection of a benign giant cell tumor at the base and shaft of the first metacarpal of the left thumb. Because of the loss of the CMC-1 joint and the instability of the thumb, an osseous reconstruction using a vascularized fibular graft combined with a TOUCH Dual Mobility CMC-1 prosthesis was performed to reconstruct the CMC-1 joint. RESULTS: Osseous healing was observed after 3 months. No tumor recurrence and good joint function were documented at the follow-up investigation after 1 year. The patient reported only minor restrictions during activities of daily living. Thumb opposition was possible with a Kapandji score of 8/10. A slight pain while walking remained as a donor-side morbidity at the right lower leg. CONCLUSION: Metacarpal reconstruction with vascularized fibula bone grafts allowed a combined joint reconstruction with a commercially available prosthesis, which is an approach to restore the complex range of motion of the thumb.

U-shaped kirschner wire transfixation: effective treatment for Skier's thumb.

BACKGROUND: Skier's thumb is a type of injury to the ulnar collateral ligament of the metacarpophalangeal joint of the thumb, which can result in bone fragmentation and joint instability. OBJECTIVE: The objective of this study was to compare the traditional Kirschner wire fixation method with the U-shaped Kirschner wire method for treating small bone fragments with displacement, rotation, or instability in skier's fractures. METHOD: A retrospective study was conducted on 30 patients with skier's thumb who were treated at Tianjin Hospital from January 2019 to December 2021. Patients were divided into two groups: Group A received traditional Kirschner wire fixation, while Group B received U-shaped Kirschner wire fixation. Functional assessments and complications during the perioperative period were evaluated. RESULTS: Both surgical methods significantly reduced postoperative pain and increased joint range of motion. Group B had a lower incidence of pain during follow-up and showed significant functional improvement in Tip-pinch and Grip tests compared to Group A. U-shaped Kirschner wire fixation significantly reduced complications during the perioperative period. CONCLUSION: The U-shaped Kirschner wire internal fixation is a safe and effective treatment for the thumb proximal phalanx base ulnar side avulsion fracture.

The Validity and Responsiveness of the Patient-Specific Functional Scale in Patients With First Carpometacarpal Osteoarthritis.

PURPOSE: The purpose of this study was to assess the content, construct, and discriminative validity and responsiveness of the Patient-Specific Functional Scale (PSFS) in patients with thumb carpometacarpal arthritis. METHODS: Data were collected at Xpert Clinics, comprising 34 outpatient hand surgery and hand therapy clinics in the Netherlands. We included 267 patients for content validity and 323 patients for construct validity and responsiveness. The PSFS items were classified into the International Classification of Function Core Set for Hand Conditions to assess content validity. We used hypothesis testing to investigate the construct validity and responsiveness. The Michigan Hand Outcomes Questionnaire was used as a comparator instrument. The standardized response mean was calculated to evaluate the magnitude of change. For discriminative validity, we used independent t tests to discriminate between satisfied and dissatisfied patients. RESULTS: We classified 98% of the PSFS items in the International Classification of Function "activities" and "participation" domains, indicating good content validity. Two of six hypotheses for construct validity and three of six hypotheses for responsiveness were confirmed. The standardized response mean for the PSFS was 0.57 (0.46-0.68) and 0.47 (0.35-0.58) for the Michigan Hand Outcomes Questionnaire total score. The mean PSFS score showed good discriminative validity because it could distinguish between satisfied and dissatisfied patients at the 3-month follow-up. CONCLUSIONS: The PSFS scores showed good content and discriminative validity in patients with first carpometacarpal arthritis. Hypothesis testing for responsiveness and construct validity indicates that the PSFS measures a unique construct different from the Michigan Hand Outcomes Questionnaire. CLINICAL RELEVANCE: The PSFS may be a useful scale for measuring the patient-specific status of individuals with thumb carpometacarpal arthritis.