Does correction of carpal malalignment influence the union rate of scaphoid nonunion surgery?

The aim of this retrospective study was to assess the relation between carpal malalignment correction and radiological union rates in surgery for scaphoid nonunions. A total of 59 scaphoid waist fracture nonunions treated with open reduction and palmar tricortical autograft were divided according to their pre- and postoperative scapholunate (SL) and radiolunate (RL) angles. We found that carpal malalignment failed to correct in 32 of 59 (54.2%) patients despite meticulous surgical technique and placement of an appropriately sized wedge-shaped graft. In total, 43 (72.9%) fractures united at a mean of 4.47 months (range 3-11). Of the 27 fractures with postoperative SL and RL angles within the normal range, 21 united, whereas 22 of the 32 remaining fractures that failed to achieve postoperative angles within the normal range went on to union. The postoperative SL and RL angles were not related to union. Our findings suggest that in scaphoid fracture nonunion surgery, carpal malalignment may not be corrected in a substantial proportion of patients, but such correction may not be essential for bony union. Our findings also show that there is no marked collapse of the scaphoid graft in the early postoperative period.

LEVEL OF EVIDENCE

IV.

Carpal fractures: epidemiology, classification and treatment of 6542 fractures from the Swedish Fracture Registry

This study describes the age and sex distribution, trauma mechanism, treatment and influence of patient-reported outcomes of 6542 carpal fractures from the Swedish Fracture Registry (SFR). The most commonly fractured carpal bone was the scaphoid (60%), followed by the triquetrum (25%), hamate (5%) and trapezium (4%). The mean age at injury was 41 years, and 69% of patients were male. The age and sex distribution of carpal fractures differed substantially between the different carpal bones. Men were more likely to sustain a carpal fracture after high-energy trauma and were more likely to be treated surgically. Carpal fractures had a small negative effect on the Short Musculoskeletal Function Assessment Hand/Arm Index and EQ-5D scores 1 year after the injury.Level of evidence: IV.

Infrared Spectroscopy of Synovial Fluid Shows Accuracy as an Early Biomarker in an Equine Model of Traumatic Osteoarthritis

Osteoarthritis is a leading cause of lameness and joint disease in horses. A simple, economical, and accurate diagnostic test is required for routine screening for OA. This study aimed to evaluate infrared (IR)-based synovial fluid biomarker profiling to detect early changes associated with a traumatically induced model of equine carpal osteoarthritis (OA). Unilateral carpal OA was induced arthroscopically in 9 of 17 healthy thoroughbred fillies; the remainder served as Sham-operated controls. The median age of both groups was 2 years. Synovial fluid (SF) was obtained before surgical induction of OA (Day 0) and weekly until Day 63. IR absorbance spectra were acquired from dried SF films. Following spectral pre-processing, predictive models using random forests were used to differentiate OA, Sham, and Control samples. The accuracy for distinguishing between OA and any other joint group was 80%. The classification accuracy by sampling day was 87%. For paired classification tasks, the accuracies by joint were 75% for OA vs. OA Control and 70% for OA vs. Sham. The accuracy for separating horses by group (OA vs. Sham) was 68%. In conclusion, SF IR spectroscopy accurately discriminates traumatically induced OA joints from controls.

Outcomes of Endoscopic Carpal Tunnel Release Surgery With Home Guided Hand Therapy Versus No Hand Therapy: A Prospective Randomized Controlled Trial After Endoscopic Carpal Tunnel Release

BACKGROUND

The most recent American Academy of Orthopaedic Surgeons Clinical Practice Guidelines found no high-quality evidence comparing home therapy to no therapy following carpal tunnel release surgery (CTRS). Therefore, this study's purpose is to compare the outcomes of patients receiving home therapy and patients receiving no therapy following endoscopic CTRS.

METHODS

A single-blinded prospective randomized controlled trial was performed. Patients were randomized to receive home hand therapy or no therapy postoperatively. Patients were assessed at baseline, 2, 6, and 12 weeks postoperatively. Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores and Boston Carpal Tunnel Questionnaire (BCTQ) scores were evaluated as primary outcome measures. Grip strength, pinch strength, numerical pain rating scale (NRS), static 2-point discrimination, and hand circumference were also measured.

RESULTS

Fifty patients were randomized to home therapy while 55 patients were randomized to no therapy. The QuickDASH, BCTQ functional status scale (FSS), and BCTQ symptom severity scale (SSS) improved over time in both treatment groups. As-treated and intention-to-treat analysis showed no difference in improvement of QuickDASH, BCTQ FSS, or BCTQ SSS between treatment groups. Additionally, there was no significant difference between treatment groups in grip strength, chuck and key strength, NRS, hand circumference, and static 2-point discrimination.

CONCLUSIONS

This blinded, prospective randomized controlled study shows no significant difference in improvement of QuickDASH, BCTQ SSS, and BCTQ FSS scores between patients receiving no therapy and home therapy following endoscopic CTRS. Consideration should be given to releasing patients without supervised therapy in the postoperative setting.

LEVEL OF EVIDENCE

Level II Therapeutic.

A Case for Acute Proximal Row Carpectomy for Perilunate Injuries

Background

Perilunate injuries are complex injuries typically arising from high-energy injuries to the wrist. Standard treatment involves open reduction and internal fixation with ligamentous reconstruction; however, outcomes are fraught with complications including pain, stiffness, and arthrosis. Several case reports have demonstrated the role of proximal row carpectomy as a salvage procedure for complex carpal trauma in the setting of significant cartilage injury or bone loss. The authors believe that proximal row carpectomy may be an appropriate acute treatment in certain patient populations, with functional results similar to those obtained with ligamentous reconstruction.

Methods

A retrospective review of two cases with perilunate dislocations managed with primary proximal row carpectomy are presented.

Results

At greater than 1-year follow-up, both patients had stable radiocarpal alignment. Quick-DASH scores were 22.7 and 27.3.

Conclusion

Primary proximal row carpectomy is a treatment option in the acute setting for perilunate injuries in elderly, lower-demand patients. Functional results are similar to those obtained with ligamentous reconstruction, with a shorter recovery period. Level of Evidence: IV.

Association of ulnar variance with three-dimensional carpal alignment and demographics in asymptomatic volunteers

BACKGROUND

Several carpal pathologies are considered to be related to ulnar variance. Recently, computer-aided computed tomography (CT) analysis software was introduced to quantify three-dimensional (3D) carpal alignment with high accuracy and reliability.

PURPOSE

To determine the association of ulnar variance with 3D carpal alignment and demographics.

MATERIAL AND METHODS

A wrist of 121 asymptomatic volunteers (69 men, 52 women; mean age = 38 ± 10.4 years) was imaged in the neutral wrist position with cone-beam CT. Computer-aided CT analysis software (Bonelogic), based on segmentation and numerical modelling, was used to define ulnar variance and standardized 3D axes for all carpal bones. The association of ulnar variance with 3D carpal alignment, age of the volunteer, and side and dominance of the imaged wrist was assessed.

RESULTS

The mean ulnar variance was -1.6 ± 1.5 mm (range = -5.3 to 2.4 mm). The mean ulnar variance was -1.9 mm and -1.1 mm in men and women (P = 0.007), respectively. Of the imaged 121 wrists, 18 (15%) had positive and 103 (85%) negative ulnar variance. There was no association between ulnar variance and any of the radio- or intercarpal angle values in either the sagittal or coronal plane (ρ = -0.16…0.17, r = -0.13….0.12). The ulnar variance showed no association with side (P = 0.51) or dominance (P = 0.27) of the imaged wrist.

CONCLUSION

3D carpal alignment is not affected by ulnar variance. The association of ulnar variance with sex may in part explain the difference in reported prevalence of some carpal pathologies, such as ulnar impaction syndrome and Kienböck's disease.

Biomechanical Performance of Total Wrist Arthrodesis Plates With and Without Arthrodesis of the Carpometacarpal Joint

BACKGROUND

It is unknown whether total wrist arthrodesis (TWA) should be performed with or without arthrodesis of the carpometacarpal joint (CMCJ). The aim of this study is to compare CMCJ-spanning TWA plates using 3D printed wrist arthrodesis model with and without arthrodesis of the CMCJ.

METHODS

Total wrist arthrodesis plates mounted to 3D printed models were tested under a 4-N bending load at 4 Hz for 50 000 cycles, increased by 15% every 10 000 cycles until failure.

RESULTS

Plates with arthrodesis CMCJ were stiffer and failed at a significantly greater load and number of cycles than plates mounted to models without CMCJ arthrodesis. The Synthes stainless steel locking TWA plate performed better than the Trimed plate applied to the model without CMCJ arthrodesis and the Acumed plate applied to the model with CMCJ arthrodesis. Based on these findings, we recommend arthrodesis of the CMCJ in TWA.

CONCLUSIONS

Incorporation of the CMCJ in TWA may protect against plate failure. If arthrodesis of the CMCJ is not performed, plate removal should be considered before breakage occurs.

LEVEL OF EVIDENCE

IV.

Principal component and linear discriminant analyses for the classification of hominoid primate specimens based on bone shape data

In this study, we tested the hypothesis that machine learning methods can accurately classify extant primates based on triquetrum shape data. We then used this classification tool to observe the affinities between extant primates and fossil hominoids. We assessed the discrimination accuracy for an unsupervised and supervised learning pipeline, i.e. with principal component analysis (PCA) and linear discriminant analysis (LDA) feature extraction, when tasked with the classification of extant primates. The trained algorithm is used to classify a sample of known fossil hominoids. For the visualization, PCA and uniform manifold approximation and projection (UMAP) are used. The results show that the discriminant function correctly classified the extant specimens with an F1-score of 0.90 for both PCA and LDA. In addition, the classification of fossil hominoids reflects taxonomy and locomotor behaviour reported in literature. This classification based on shape data using PCA and LDA is a powerful tool that can discriminate between the triquetrum shape of extant primates with high accuracy and quantitatively compare fossil and extant morphology. It can be used to support taxonomic differentiation and aid the further interpretation of fossil remains. Further testing is necessary by including other bones and more species and specimens per species extinct primates.

Imaging Diagnosis and Management of Carpal Trauma and Instability-An Illustrated Guide

Understanding the subtle signs of carpal instability and other unique injury patterns in the wrist is a critical skill for radiologists. Proper patient management and outcomes are directly dependent on the accurate interpretation of wrist imaging studies. This review will provide a detailed overview of typical imaging features of carpal trauma and instability, management, and complications, using multimodality imaging and original medical illustrations. A detailed overview of the osseous, ligamentous, arterial anatomy of the wrist, arcs of Gilula, and zones of vulnerability will be provided. Carpal fractures, dislocations, special radiographic views, and imaging pearls will be discussed. Instability patterns and the myriad of associate abbreviations (CID, CIND, CIC, CIA, VISI, DISI, SLD, LTD, MCI, SLAC, SNAC) will be clarified. Expected outcomes, potential complications, and management will be reviewed.

A Comparative Study of 2-Corner, 3-Corner, and 4-Corner Arthrodesis for Midcarpal Arthritis

BACKGROUND

Four-corner fusion (4CF) is a common treatment for midcarpal arthritis; however, alternatives including 2-corner fusion (2CF) and 3-corner fusion (3CF) have been described. Limited literature suggests 2CF and 3CF may improve range of motion but have higher complication rates. Our objective is to compare function and patient-reported outcomes following 4CF, 3CF, and 2CF at our institution.

METHODS

Adult patients undergoing 4CF, 3CF, and 2CF from 2011 to 2021 who attended at least one follow-up were included. Four-corner fusion patients were compared with those who underwent either 3CF or 2CF using staple fixation. Outcomes include nonunion rate, reoperation rate, progression to wrist fusion, range of motion, and patient-reported pain, satisfaction, and Disabilities of the Arm, Shoulder, and Hand (DASH) scores.

RESULTS

A total of 58 patients met inclusion criteria. There were 49 4CF and 9 2CF or 3CF patients. Nonunion rates, progression to wrist fusion, and repeat surgery for any indication were not significantly different among groups. Range of motion (flexion-extension, radial-ulnar deviation) and grip strength at postoperative visits were not significantly different. Significantly more 4CF patients required bone grafting. Pain, overall satisfaction, and DASH scores were similar.

CONCLUSIONS

Although prior studies suggest increased risk of nonunion and hardware migration after 2CF/3CF, we did not observe higher complication rates compared with 4CF. Range of motion, strength, and patient-reported outcomes were similar. While 4CF is traditionally the procedure of choice for midcarpal fusion, we found that when using a staple fixation technique, 2CF and 3CF have comparable clinical and patient-reported outcomes yet decrease the need for autologous bone grafting.

Successful closed reduction of a trans-scaphoid perilunate dislocation in a 11-year-old boy: a case report

CASE

Perilunate dislocation is an uncommon injury in children. We report the case of an 11-year-old boy who presented a trans-scapho-perilunate fracture-dislocation of the carpus after falling from his bike. Treatment consisted of a closed reduction under general anesthesia followed by cast immobilization for 12 weeks. The injury healed with good wrist function on follow-up.

CONCLUSION

Closed reduction should be attempted because it can be successful and allows for closed treatment with the cast. It provides good radiological healing and satisfying functional results.

A radiographic study of dorsovolar wrist axes and a database of angular measurements on axial computed tomography images

OBJECTIVES

This study aims to identify the most accurate dorsovolar principal axis of the distal radius and carpus identified on axial computed tomography (CT) sections and to establish normative data for angular measurements among these axes.

PATIENTS AND METHODS

Between December 2019 and December 2021, normal axial CT images of wrists of a total of 42 individuals (25 males, 17 females; mean age: 31±8.4 years; range, 18 to 45 years) were retrospectively analyzed. Eight axes were identified on axial CT images: four distal radial axes (the volar cortical, medial cortical, central, and sigmoid notch axes) and four carpal axes (the scapholunate, lunotriquetral, capitohamate, and pisotrapezial axes). Twenty-two angular parameters were measured with reference to four principal axes (the volar cortical, medial cortical, central, and pisotrapezial axes).

RESULTS

The mean sigmoid notch rotation (version) angles relative to the four principal axes were 8±5° (range, -2° to 18°), 6±5° (range, -2° to 13°), 1±5° (range, -8° to 14°), and 4±4° (range, -3° to 15°), respectively. The mean scapholunate rotation angles were -13±5° (range, -27° to -6°), -15±6° (range, -29° to -8°), -21±5° (range, -30° to -11°), and -8±5° (range, -28° to -6°), respectively. Among four principal axes, the volar cortical and medial cortical axes were nearly collinear with both of relatively fixed carpal axes. The four principal axes showed angular differences between 2° and 8° with each other. There was no significant difference between men and women for all measurements.

CONCLUSION

The axial CT sections can be used to describe the various angulations between the normal wrist axes such as the sigmoid notch and scapholunate joint rotation angles. Despite slight differences among the four principal axes, the volar cortical and medial cortical axes are more consistent with the relatively fixed carpal axes.

A Descriptive Study of the Carpal Joint of Healthy Donkeys Using Ultrasonography, Computed Tomography, and Magnetic Resonance Imaging

This study was conducted to establish a detailed anatomic reference for the carpal joint of apparently healthy donkeys using ultrasonography (US), computed tomographic (CT), and magnetic resonance imaging (MRI). Ten orthopedically sound adult donkeys were used for US examination of the carpal joint in each forelimb. Additionally, the carpi of ten donkey cadavers were subjected to CT and MRI examinations. The carpal joint was divided into four zones to simplify examination. US assessment of the carpal joint included transverse and longitudinal sonograms. CT was performed using three planes: axial, sagittal, and coronal. MRI was performed using axial and sagittal planes with two sequences: gradient-echo T1-weighted and proton density. The donkeys’ carpus US, CT, and MRI images were labeled and serially interpreted based on references and anatomical cross-sections. The anatomical characteristics of the carpal joint and the surrounding soft tissue structures were thoroughly described and precisely differentiated on US, CT, and MRI scans. It can be concluded that US, CT, and MRI are effective noninvasive diagnostic imaging tools for evaluating the carpal joint in donkeys. Moreover, these imaging modalities can aid in establishing a reference database for the carpal joint of donkeys, which differs from that of horses.

Sonoanatomy and Stepwise/Systematic Ultrasound Examination of the Extrinsic/Intrinsic Wrist Ligaments

Ultrasound has emerged as the most useful imaging tool for investigating wrist and hand disorders, with several published ultrasound protocols having demonstrated their practicality in scanning the wrist tendons and nerves. However, ligaments of the wrist are networked in a complex manner, deterring sonographers from examining them with an organized strategy. Furthermore, because of the non-parallel alignment between the radiocarpal, mid-carpal, and carpal-metacarpal joints, precise recognition of the carpal bones is challenging, although ultrasound is paramount for visualizing the wrist ligaments. In this regard, the current article for point of view aims to elaborate sonoanatomy of the carpal bones and to present a stepwise systematic approach for navigating the extrinsic and intrinsic wrist ligaments.

Ulnar-sided wrist pain: a prospective analysis of diagnostic clinical tests

BACKGROUND

Identifying the cause of pain on the ulnar side of the wrist can be challenging. The outcome and recovery following surgery can be unpredictable. The aim of this study was to document and analyse the clinical tests used to evaluate the cause of ulnar-sided wrist pain and determine their diagnostic relevance.

METHODS

This is a prospective evaluation of 110 patients who presented with pain on the ulnar side of the wrist. The clinical evaluation and results from radiological investigations were documented and analysed.

RESULTS

There were 17 different diagnoses. Eighty-five percent of the diagnoses were triangular fibrocartilage complex (TFCC) injuries, ulnocarpal abutment syndrome (UCAS), pisotriquetral arthritis (PTA), triquetral fracture or non-union, distal radioulnar joint arthritis (DRUJ OA) and extensor carpi ulnaris (ECU) pathology. The ulnocarpal stress test and ulnar foveal sign were positive in several diagnoses. The ulnar foveal sign had a sensitivity and specificity of 89% and 48% for TFCC injuries, and 85% and 37% for UCAS, respectively. The sensitivity and specificity of pisotriquetral shear test for PTA was 100% and 92%, respectively. Patients with PTA or ECU pathology localised their pain better on the patient's pain localisation chart.

CONCLUSION

Diagnosis of TFCC injuries, UCAS, DRUJ OA and ECU injuries are challenging as the clinical symptoms and signs for the four diagnoses were similar and required either magnetic resonance imaging or computed tomography for diagnostic confirmation after clinical examination. The ulnocarpal stress test and the ulnar foveal sign were not sufficiently specific.

Functional signals and covariation in triquetrum and hamate shape of extant primates using 3D geometric morphometrics

In this study, we want to investigate the covariation in the shape of two carpal bones, the triquetrum and hamate, and the possible association with locomotor behavior in a broad range of primate taxa. We applied 3D Geometric Morphometrics on a large data set comprising 309 anthropoid primates of 12 different genera. Principal component analyses were performed on the covariance matrix of 18 (triquetrum) and 23 (hamate) Procrustes-aligned surface landmarks. A two-block partial least square analysis was done to test the covariance between triquetrum and hamate shape, without relying on the predictive models implicit in regression analyses. The results show that the carpal shape of quadrupedal anthropoids, which mainly use their wrist under compressive conditions, differs from that of suspensory primates as their wrist is possibly subjected to tensile and torsional forces. Within the hominids, differences in shape also distinguish more terrestrial from more arboreal species. Even within the great apes, we are able to capture shape differences between species of the same genus. In combination with behavioral and biomechanical studies, the results of this research can be used to establish form-function relationships of the primate hand which will aid the functional interpretation of primate fossil remains.

Dorsal Dislocation of the Trapezoid with Metacarpal Instability: A Boxing Injury

Background  The second and third metacarpals are firmly attached, immobile structures which for the stable pillar of the hand. The trapezoid has been described as the keystone of the wrist, allowing a wide range of functional motion as well as inherent anatomic and biomechanical stability to the carpus. Case Description  We describe a novel boxing injury with a 180-degree in situ dislocation of the right trapezoid with concomitant second and third carpometacarpal (CMC) joint dislocations. Open anatomic reduction of the trapezoid was obtained, and subsequent percutaneous pinning of the metacarpals allowed for a full functional recovery and return to sports at 6 months. Literature Review  Combined trapezoid and CMC dislocations are extremely rare and have only been previously described in high-energy mechanism injuries, involving a direct dorsal force such as from the steering wheel in a motor vehicle collision. There are no previous reports of this injury occurring in the setting of direct axial load along the metacarpals in a clenched fist such as in a punch or fighting injury. Clinical Relevance  The rare nature of this combined injury, its novel mechanism, and the difficulty in interpreting acute injury and postreduction radiographs require that the treating physician have a high degree of clinical suspicion for associated injuries when CMC dislocations are identified. Treatment strategies incorporating intraoperative fluoroscopy, open anatomic reduction of the trapezoid under direct visualization along with closed reduction, and pinning of the metacarpals reestablish carpal stability and provide excellent long-term results.

Giant Cell Tumor of Triquetrum: A Case Report with Literature Review

Background  Giant cell tumor (GCT) of bone is a benign, aggressive tumor of bone and occurs commonly around the knee and distal radius. GCT of bone rarely occurs in hand. In hand, metacarpals are the most common site and there have been only a few case reports of GCT of the carpal bone. In hand, these tumors are very aggressive and these have a high tendency to recur after intralesional curettage. No long-term study is available for choosing an appropriate method of treatment for these tumors in hand. Case Description  Herein, we report a case of GCT of the bone involving triquetrum which was managed by excision of triquetrum and scaphoid bone. The reconstruction of the wrist was done through limited carpal fusion, by doing three corner fusion of the wrist. At 2 years after surgery, the patient was asymptomatic and radiographs revealed fusion of lunocapitate and lunohamate joints with no evidence of recurrence. Literature review  Current literature regarding GCT of triquetrum includes case reports that are reviewed in this report. Clinical Relevance  This case illustrates the successful treatment of GCT of triquetrum, which is a rare tumor. Three-corner fusion is a reliable and reproducible procedure that has been used for other arthritic conditions. The use of three corner fusion procedure can be extended to GCT of carpal bones. It has been a motion-preserving alternative to proximal row carpectomy.

A Controlled Trial Evaluating the Safety and Effectiveness of Ultrasound-Guided Looped Thread Carpal Tunnel Release

Background: Open carpal tunnel release typically requires several weeks of recovery. A less invasive, ultrasound-guided percutaneous technique of releasing the transverse carpal ligament using a thread (thread carpal tunnel release [TCTR]) has been described. To date, its clinical effectiveness and safety have been evaluated exclusively by the group that developed the technique, using a single outcome measure without a control comparison. The objective of this study was to independently evaluate the safety and effectiveness of TCTR using multiple outcome measures and a control comparison. Methods: A convenience sample of 20 participants with refractory moderate or severe carpal tunnel syndrome underwent TCTR of their most symptomatic hand. Outcome measures included pre-TCTR and 1-, 3-, and 6-month post-TCTR Boston questionnaire; pre-, 3-, and 6-month post-TCTR monofilament sensibility, strength, ultrasound, and electrodiagnostic testing; weekly post-TCTR phone interviews for 1 month; and satisfaction surveys at 3 and 6 months post-TCTR. Results: No complications were reported. During the month post-TCTR, significant prompt improvements in hand pain and dysfunction occurred. The following significant improvements were demonstrated in the treated versus control hand: Boston Questionnaire scores, median nerve distal motor latency, transcarpal tunnel motor and sensory conduction velocities and sensory nerve action potential amplitudes. No significant differences in sensibility, pinch or grip strength, median nerve cross-sectional area (CSA) at the carpal tunnel inlet, or wrist: forearm median nerve CSA ratio were documented between TCTR and control sides. Satisfaction with the TCTR procedure was high (85%-90%). Conclusions: This study supports previous reports that the TCTR procedure is safe and effective.

Prevalence of Hypothyroidism Among Carpal Tunnel Syndrome Patients at a Hospital in Saudi Arabia

Introduction

Patients with carpal tunnel syndrome have a high prevalence of hypothyroidism, therefore, it is recommended to assess thyroid function routinely in patients with carpal tunnel syndrome. This study aims to determine the prevalence of hypothyroidism among carpal tunnel patients and to relate carpal tunnel in hypothyroidism to other socio-demographic factors.

Methods

This was a retrospective study carried out in King Fahad Medical City (KFMC) in Riyadh, Saudi Arabia. A total of 422 samples were collected conveniently from the files of patients who underwent carpal tunnel release surgery. The Statistical Package for the Social Sciences (SPSS) version 23 was used for data processing. The chi-square test was used to test the association between the categorical variables. A p-value of less than .05 was considered to be significant.

Results

Most of the respondents were females and most of them within the age group of 46 to 60 years. Thirteen point eight percent (13.8%) of the respondents are suffering from hypothyroidism and 5% from the sub-clinical form of the disease. More than two-thirds of those with hypothyroidism were asymptomatic. The duration of the disease was one to five years, and bilateral nerve concerns were mostly present in patients with carpal tunnel syndrome. The presence of thyroid abnormality doesn’t affect the duration of carpal tunnel syndrome but body mass index (BMI) is significantly associated with hypothyroidism (p-value = .001).

Conclusion

Clinical symptoms of hypothyroidism are mostly absent in patients with carpal tunnel syndrome. Most patients with carpal tunnel syndrome have the disease for one to five years and this is not significantly associated with abnormal thyroid. Most patients have bilateral wrist involvement with no apparent symptoms and signs.

Bupivacaine Extended-Release Liposomal Injection Versus Bupivacaine HCl for Early Postoperative Pain Control Following Wrist Operations: A Prospective, Randomized Control Trial

PURPOSE

This study evaluated pain control after wrist operations using a long-acting local anesthetic, liposomal bupivacaine, compared with the standard local anesthetic, bupivacaine HCl.

METHODS

Patients undergoing elective carpometacarpal joint arthroplasty and proximal row carpectomy were eligible. Those meeting inclusion criteria were enrolled before surgery and were randomized to receive an intraoperative injection of liposomal bupivacaine or bupivacaine HCl. Primary outcomes included intraoperative and postoperative opioid requirements and pain levels. On the first 4 postoperative days, phone contact assessed pain level by numeric rating scale, number of opioids taken in each 24-hour period, and efficacy of anesthesia and opioid side effects with overall benefit of analgesia score.

RESULTS

Postoperative pain scores for 52 patients measured by numeric rating scale demonstrated that liposomal bupivacaine and bupivacaine HCl were similar for pain control. Pain scores and opioid use were similar during the first 4 postoperative days. Opioid use on day 1 was slightly lower with liposomal bupivacaine. There were no statistically significant differences in any postoperative outcome between groups.

CONCLUSIONS

Liposomal bupivacaine and bupivacaine HCl have similar effects in the treatment of early postoperative pain after trapeziometacarpal suspension arthroplasty and proximal row carpectomy. Neither drug demonstrated a clear advantage in this study.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic II.

Medial Femoral Trochlea Graft for Scaphoid Waist Nonunion: A Case Report and Review of the Literature

The medial femoral trochlea (MFT) of the knee is a donor site for convex osteochondral vascularized bone that has been used for the salvage of fractures of the proximal pole of the scaphoid. Chronic nonunited fractures of the scaphoid may lead to a sequence of degenerative change often referred to as scaphoid nonunion advance collapse. The vascularized MFT osteochondral graft has been reported as a salvage procedure for fractures of the proximal pole of the scaphoid, in situations where fixation is not an option. In this "Special review," we describe the technique of free vascularized MFT graft in a case in which the nonunited scaphoid fracture was associated with segmental loss of the articular surface of the scaphoid waist. Given the likely progression of arthritis, if left untreated, we elected to treat this by replacing the lost articular surface using a vascularized intercalary osteochondral MFT graft between the nonunited scaphoid segments.

Transscaphoid Dorsal Lunate Dislocation: A Case Presentation and Review of the Literature

This case report describes a 74-year-old man with the rare injury of transscaphoid dorsal lunate dislocation (LD). He sustained a crushing injury with a huge amount of energy to his right wrist while working with a pressing machine. There were deep abrasions and areas of skin necrosis on the dorsum of the wrist. The patient was treated with closed reduction and a Herbert screw fixation for the scaphoid fracture. Six months postoperatively, avascular necrosis (AVN) of the lunate and scaphoid was apparent on the wrist radiographs. We offered a proximal row carpectomy to the patient, but he declined surgery because he was able to perform his activity of daily living. Dorsal LD as well as its variants has a high prevalence of AVN of the lunate. Delayed diagnosis, delayed treatment, and open reduction increase the risk of AVN development of the lunate. The level of evidence is therapeutic IV.

Nonoperative Treatment of Ulnar Carpometacarpal Fracture-Dislocations

Background  Ulnar carpometacarpal (CMC) joint dislocations and fracture-dislocations are uncommon injuries that are often overlooked. Most authors advocate surgical stabilization in order to prevent a secondary dislocation assuming that these injuries are inherently unstable. Case Description  This is a series of eight ulnar CMC joint dislocations and fracture-dislocations treated by closed reduction and splint immobilization after assessing the joint stability. Mean follow-up was 30.2 months, and minimum follow-up was 12 months. Satisfactory results were obtained in range of motion, grip strength, pain, DASH (Disabilities of the Arm, Shoulder and Hand) questionnaire, and time to return to working activities. In the same period, the closed reduction and cast failed two (20%) cases that were referred for surgery. Literature Review  There is little published literature on the nonoperative treatment of these injuries. Most of them are isolated case reports, whereas the largest series reports four cases. All of them have reported satisfactory results. Clinical Relevance  Based on our results, we believe that if the diagnosis of an ulnar CMC joint dislocation or fracture-dislocation is early accomplished and a concentric and stable reduction is initially achieved, the nonoperative treatment may be a successful option to take into account but requiring a close follow-up for the first week.

Accelerated Evolution of Limb-Related Gene Hoxd11 in the Common Ancestor of Cetaceans and Ruminants (Cetruminantia)

Reduced numbers of carpal and tarsal bones (wrist and ankle joints) are extensively observed in the clade of Cetacea and Ruminantia (Cetruminantia). Homebox D11 (Hoxd11) is one of the important genes required for limb development in mammals. Mutations in Hoxd11 can lead to defects in particular bones of limbs, including carpus and tarsus. To test whether evolutionary changes in Hoxd11 underlie the loss of these bones in Cetruminantia, we sequenced and analyzed Hoxd11 coding sequences and compared them with other 5′ HoxA and HoxD genes in a taxonomic coverage of Cetacea, Ruminantia and other mammalian relatives. Statistical tests on the Hoxd11 sequences found an accelerated evolution in the common ancestor of cetaceans and ruminants, which coincided with the reduction of carpal and tarsal bones in this clade. Five amino acid substitutions (G222S, G227A, G229S, A240T and G261V) and one amino acid deletion (G254Del) occurred in this lineage. In contrast, other 5′ HoxA and HoxD genes do not show this same evolutionary pattern, but instead display a highly conserved pattern of evolution in this lineage. Accelerated evolution of Hoxd11, but not other 5′ HoxA and HoxD genes, is probably related to the reduction of the carpal and tarsal bones in Cetruminantia. Moreover, we found two amino acid substitutions (G110S and D223N) in Hoxd11 that are unique to the lineage of Cetacea, which coincided with hindlimb loss in the common ancestor of cetaceans. Our results give molecular evidence of Hoxd11 adaptive evolution in cetaceans and ruminants, which could be correlated with limb morphological adaptation.

The bilaterality of idiopathic carpal tunnel syndrome among manual workers

OBJECTIVES

To evaluate: a) the prevalence of bilateral idiopathic carpal tunnel syndrome (CTS) in manual workers; b) a correlation between the duration of unilateral and bilateral CTS symptoms; c) a correlation between the onset of CTS symptoms in the unilateral dominant/non-dominant hand and the time of developing bilateral CTS; and d) findings of the nerve conduction study (NCS) in symptomatic and asymptomatic hands of patients with unilateral CTS.

MATERIAL AND METHODS

Clinical and neurophysiological examinations were conducted along with a detailed analysis of job exposure of 332 manual workers admitted to the Occupational Medicine Department, the Nofer Institute of Occupational Medicine, with suspected occupational CTS. Eventually, 258 patients were excluded from the study: 34 with associated neuropathies and 206 with other conditions potentially associated with CTS. Cases with work-related CTS (18) were also excluded.

RESULTS

A total of 74 patients were diagnosed as idiopathic CTS. In idiopathic CTS, the right hand was affected in 15 (20.3%) patients, the left hand in 4 (5.4%) patients, and both hands in 55 (74.3%) patients. Symptoms duration was longer in the patients with bilateral CTS (4.01 years) than in those with a unilateral right (1.7 years, p = 0.002) or left hand condition (2.8 years, p = 0.313). Median nerve impairment at the wrist was revealed by NCS in 6 left and 2 right asymptomatic hands.

CONCLUSIONS

The findings of the study indicate the need for "alerting" patients with unilateral CTS about the risk of the disease developing in the contralateral hand. Therefore, NCS should be routinely performed in the asymptomatic hands of patients with unilateral CTS, which is essential for the prevention of neuropathies, especially among manual workers performing repetitive manual tasks. Int J Occup Med Environ Health. 2020;33(2):151-61.

"Locked" Scapholunate Instability Diagnosed with 4D Computed Tomography Scan

Background  Scapholunate instability (SLI) has a wide range of clinical and radiological presentations. The management depends on the stage of the disorder. Subluxation of scaphoid is pathognomonic feature of the SLI. We describe a patient with SLI with a dislocated proximal pole of scaphoid, out of the distal radius scaphoid fossa. The 4D (three-dimensions + time) computed tomography (CT) scan demonstrated that the scaphoid did not reduce throughout wrist motion. Case Description  A 20-year-old male presented with SLI following a fall skateboarding. The 4D CT scan revealed the dislocated scaphoid that did not reduce with wrist motion. He underwent open reduction of the proximal pole of scaphoid and SL reconstruction using flexor carpi radialis (FCR) tendon graft with the Quad tenodesis technique. At 1 year, he had improved pain, wrist functions, and maintained satisfactory radiological alignment. Literature Review  We are not aware of any previous description of the dorsal scaphoid dislocation in association with scapolunate instability. Clinical Relevance  We recommend that the SLI staging classification needs to be expanded to include dislocation (locked) stage. The 4D CT has a significant role in identifying the instability and its reducibility. Level of Evidence  This is a level V study.

Management Modalities and Outcomes Following Acute Scaphoid Fractures in Children: A Quantitative Review and Meta-Analysis

BACKGROUND

Early evaluation and appropriate management of pediatric scaphoid fractures are necessary to avoid complications. To date, current management of pediatric fractures varies among providers. The objective of this study was to compare clinical outcomes following different treatment modalities.

METHODS

A PubMed literature search identified studies involving acute scaphoid fractures in children. Studies were evaluated for treatment provided and their respective effects on union rate, wrist range of motion, and wrist pain. Data were pooled across studies, and quantitative statistical analysis was conducted to compare outcomes.

RESULTS

Seventeen studies representing 812 acute pediatric scaphoid fractures were included in the current analysis. We found 93.5% of scaphoid fractures were treated with cast immobilization vs 6.5% treated surgically as 13 of 17 authors treated all fractures with immobilization vs 4 of 17 studies who offered surgical intervention. We found pediatric scaphoid fractures had excellent bone union rates (96.2%) with no difference between the cast immobilization and surgery groups ( P value NS). Long- and short-arm thumb spica immobilization protocols were commonly employed; however, we found no difference in the rates of union ( P value NS). At follow-up, 99.0% of patients treated nonoperatively had normal wrist range of motion and 96.8% were pain free.

CONCLUSIONS

Pediatric scaphoid fractures have excellent outcomes. Nonoperative treatment results in a high rate of union with few posttreatment wrist symptoms. Nonsurgical treatment represents an adequate treatment modality in a majority of acute pediatric scaphoid fractures, wherein the role for surgery needs to be better defined.

Induction of Synovitis Using Interleukin-1 Beta: Are There Differences in the Response of Middle Carpal Joint Compared to the Tibiotarsal Joint?

Background: The effects of recombinant interleukin-1β (rIL-1β) have been described for the middle carpal joint (MCJ). However, we are unaware of any studies that have described the cytological response of the tibiotarsal joint (TTJ) to rIL-1β or compared the clinical and cytological responses of the MCJ to the TTJ following the administration of intra-articular rIL-1β. Such information is critical for researchers planning to use rIL-1β to create acute synovitis models in horses. Objectives: To compare the clinical and cytological responses of the MCJ to the TTJ following administration of intra-articular rIL-1β. Methods: Twelve horses were used for the study. Eight horses received 75 ng of rIL-1β into the MCJ and four horses received 75 ng of rIL-1β into the TTJ. Clinical and cytological outcome parameters including lameness, joint circumference, joint effusion score, total nucleated cell count, cellular differentials, C-reactive protein, and prostaglandin-E2 concentrations were determined at baseline and multiple post-treatment time points over a 336 h period (2 weeks). Results: Recombinant IL-1β administered into the TTJ resulted in a significantly greater respiratory rate at 24 h and heart rate at 12 h when compared to rIL-1β administered into the MCJ. In addition, the TTJ had a significantly greater increase in joint circumference at 24 post-injection hour (PIH) and subjective effusion grade at 24 PIH and 336 PIH. The MCJ had significantly higher total protein concentration at 6 PIH, and a significantly higher NCC at 24 and 72 PIH when compared to the TTJ. Conversely, the TTJ had significantly higher neutrophilic infiltration than the MCJ at 6 PIH and 168 PIH. Conclusions: This study establishes that the same intra-articular dose of rIL-1 β elicits significantly different clinical and cytological responses in the MCJ compared to the TTJ in the equine model of intra-articular synovitis. In addition, clinical and cytological evidence of synovitis may persist up to or >1 week following intra-articular administration of rIL-1 β.

Patterns of Complex Carpal Injuries in the Hand from Fireworks

Purpose To describe the various patterns of complex carpal and metacarpal fracture dislocations observed in a consecutive series of firework injuries and the operative management performed. Materials and Methods We performed a retrospective study of seven consecutive patients (six males; mean age = 22 ± 13, range, 8-39 years) who presented to a level I trauma center with firework injuries to the hand between July 2014 and January 2016. Results All injuries were sustained while a lighted firework was held in the hand. The mean length of hospital stay was 13.9 ± 13.8 (range, 4-46) days with an average of 3 ± 2.6 (range, 1-7) surgeries required for both bony and soft tissue reconstruction. Three patterns of injury were seen: type I-no carpal involvement; type II-carpometacarpal joint (CMCJ) dislocations and isolated carpal dislocations; type III-CMCJ dislocations with axial carpal dissociation. One patient had a type I injury, three had a type II injury, and three had a type III injury. Of patients with a type III injury, two of the three had simultaneous axial-radial and axial-ulnar involvement as well as a midcarpal dissociation with divergent dissociation of the carpus and metacarpals. Conclusion The severity of carpal injuries resulting from fireworks is highly variable but is likely to follow predictable patterns due to the position of the hand and the location of the firework prior to explosion. Surgical reconstruction can be challenging, but adequate outcomes with a functional hand can be achieved through a systematic approach. Type of Study/Level of Evidence Therapeutic level IV.

Analgesic Consumption Following Outpatient Carpal Tunnel Release

PURPOSE

Few studies have examined the consumption of prescribed opioid medications after elective outpatient surgery. A better understanding of opioid consumption after elective upper-extremity surgery may lead to improved prescribing practices, decreased costs, and less leftover medication available for potential misuse. The goal of this study was to evaluate pain control and quantify the amount of leftover pain medication after outpatient carpal tunnel release.

METHODS

We performed a prospective study of patients scheduled for outpatient carpal tunnel surgery. All patients had failed nonsurgical treatment and had an electromyelogram/nerve conduction study confirming the clinical diagnosis. All patients were encouraged to remove the dressing on the first postoperative day. A total of 56 patients were initially enrolled in the study; 7 did not meet the inclusion criteria, which left 49 patients who completed the study. Average age was 57 years; 66% of patients were female. Information collected included analgesic prescribed, number of tablets consumed, and number of tablets remaining. Use of postoperative orthoses, complications, use of other analgesic medications, and reasons for not taking the prescribed analgesics were recorded.

RESULTS

Paracetamol with codeine and paracetamol with tramadol accounted for all prescriptions. Patients most frequently were given a prescription for 40 tablets. Average number of tablets consumed was 10 (range, 0-40 tablets). More than half of patients consumed fewer than 2 tablets. The average number of postoperative days of analgesic consumption was 2 (range, 0-7 days). Overall 1,531 tablets were leftover from the entire cohort.

CONCLUSIONS

This study demonstrates that excess prescription analgesics are being prescribed after carpal tunnel surgery.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Combined Perihamate Peripisiform and Peritrapezium Open Axial Carpal Dislocation: Description of a New Pattern of Crush Injury

BACKGROUND

Axial carpal dislocations and fracture-dislocations remain difficult to understand and to treat. The outcome is directly related to the injury pattern and long-term results are not good in most cases.

METHODS

39-year-old male admitted to our emergency department after his left hand was caught between 2 rollers for 10 minutes. He was diagnosed of an open axial carpal dislocation type B (perihamate peripisiform) and type E (peritrapezium) of Garcia-Elias. An extensive debridement, reduction of the carpometacarpal dislocations and stabilization with Kirschner wires was performed requiring a full thickness skin graft 14 days after the trauma.

RESULTS

At 4-year follow-up, he had 70° of wrist extension, and 78° of wrist flexion, grip strength of 65% compared to the healthy side and x-ray showed mild signs of osteoarthritis. He was satisfied and returned to the same job.

CONCLUSIONS

Axial carpal dislocations continue to be difficult injuries to address but also to classify. Since the prognosis depends on the injury pattern and other associated lesions, we believe that adding a type G which include the association of different patterns to the classification of Garcia-Elias could be useful not in changing the treatment but probably indicating a worse prognosis.

Review of MRI wrist examination since introduction of Medicare item number

INTRODUCTION

The Australian Health Department provided extended rebatable requesting rights to general practitioners in 2012 for magnetic resonance imaging (MRI) examinations in patients less than 16 years of age for a small set of clinically appropriate indications. Included item numbers 63522 and 63523 'referral by a medical practitioner (excluding a specialist and consultant physician) for a scan of wrist following radiographic examination where scaphoid fracture is suspected'. The aim of this study is to evaluate MRI examinations of suspected scaphoid fractures in the paediatric population following the Medicare item number introduction.

METHODS

Review of 60 consecutive MR wrist examinations requested by general practitioners and performed between 30 November 2012 and 16 July 2014 for a rebatable magnet in a private clinical setting. The indication for all studies was to exclude a clinically suspected fractured scaphoid following a normal radiograph. All patients were less than 16 years of age at time of examination.

RESULTS

Sixty examinations were performed; 51 revealed pathology (85% of cases) with nine normal examinations (15%). Twenty-nine studies revealed one of more fractures involving the carpals, metacarpals or distal radius. In total, 41 fractures were identified on MRI examination with 29 carpal bone fractures, six distal radius fractures and six metacarpal fractures.

CONCLUSIONS

The results highlight the sensitivity of MR wrist examination and its diagnostic benefit in clinically suspected paediatric scaphoid fractures. In addition, it reflects the prudent referral nature of general practitioners.

The Management of Kienböck Disease: A Survey of the ASSH Membership

Background The purpose of this study was to determine the current trends and common practices for the treatment of Kienböck disease at different stages. Question/Purpose To determine the current trends and common practices by hand surgeons for the treatment of Kienböck disease. Methods A survey with hypothetical Kienböck disease cases stratified by the Lichtman staging system was distributed to the American Society for Surgery of the Hand (ASSH) members. Questions and responses reflected common treatment strategies. Results Of a total of 375 worldwide respondents, preferred treatments of Kienböck disease were as follows: for Stage I disease, an initial trial of splinting was favored (74%), followed by radial shortening osteotomy for continued symptoms. For Stage II disease, 63% of surgeons preferred surgical intervention, particularly radial shortening osteotomy. For Stage IIIa with negative ulnar variance, 69% chose radial shortening osteotomy. Responses were heterogeneous for Stage IIIa Kienböck with positive variance, and capitate shortening osteotomy and vascularized bone grafting were preferred. Salvage procedures predominated for Stage IIIb disease, including proximal row carpectomy (PRC; 42%), intracarpal arthrodesis (21%), and total wrist fusion (10.7%). Similarly, Stage IV disease was treated by 87% of respondents by either PRC or wrist fusion. Without regard to stage of disease, 90% of participants reported using the same Lichtman staging to guide treatment and would also alter treatment strategy based upon ulnar variance. Conclusions Most respondents used Lichtman staging and ulnar variance to guide treatment decisions. Results indicate that the most common surgical treatments were radial shortening osteotomy for early disease and PRC in later stages. Level of Evidence Level IV, Economic/Decision Analysis.

Biomechanical role of the transverse carpal ligament in carpal tunnel compliance

The transverse carpal ligament (TCL) is a significant constituent of the wrist structure and forms the volar boundary of the carpal tunnel. It serves biomechanical and physiological functions, acting as a pulley for the flexor tendons, anchoring the thenar and hypothenar muscles, stabilizing the bony structure, and providing wrist proprioception. This article mainly describes and reviews our recent studies regarding the biomechanical role of the TCL in the compliant characteristics of the carpal tunnel. First, force applied to the TCL from within the carpal tunnel increased arch height and area due to arch width narrowing from the migration of the bony insertion sites of the TCL. The experimental findings were accounted for by a geometric model that elucidated the relationships among arch width, height, and area. Second, carpal arch deformation showed that the carpal tunnel was more flexible at the proximal level than at the distal level and was more compliant in the inward direction than in the outward direction. The hamate-capitate joint had larger angular rotations than the capitate-trapezoid and trapezoid-trapezium joints for their contributions to changes of the carpal arch width. Lastly, pressure application inside the intact and released carpal tunnels led to increased carpal tunnel cross-sectional areas, which were mainly attributable to the expansion of the carpal arch formed by the TCL. Transection of the TCL led to an increase of carpal arch compliance that was nine times greater than that of the intact carpal tunnel. The carpal tunnel, while regarded as a stabile structure, demonstrates compliant properties that help to accommodate biomechanical and physiological variants such as changes in carpal tunnel pressure.

Dorsal dislocation of the trapezoid with carpo-metacarpal dislocations: a case report and a description of the "missing carpal sign" on radiographs

BACKGROUND

A case report of dorsal trapezoid dislocation with index and middle carpometacarpal dislocation is described.

OBJECTIVES

On review of the literature, this rare injury is often misdiagnosed on presentation, with difficulty in reviewing initial radiographs being a key factor.

CASE REPORT

We present our case report of trapezoid dislocation and describe the "missing carpal sign" on radiographs as an aid to suspicion of diagnosis.

CONCLUSION

Trapezoid dislocation is an often-overlooked diagnosis; we present a sign to increase suspicion of injury and hence promote further investigation.

Different evolutionary pathways underlie the morphology of wrist bones in hominoids

BACKGROUND

The hominoid wrist has been a focus of numerous morphological analyses that aim to better understand long-standing questions about the evolution of human and hominoid hand use. However, these same analyses also suggest various scenarios of complex and mosaic patterns of morphological evolution within the wrist and potentially multiple instances of homoplasy that would benefit from require formal analysis within a phylogenetic context.We identify morphological features that principally characterize primate - and, in particular, hominoid (apes, including humans) - wrist evolution and reveal the rate, process and evolutionary timing of patterns of morphological change on individual branches of the primate tree of life. Linear morphological variables of five wrist bones - the scaphoid, lunate, triquetrum, capitate and hamate - are analyzed in a diverse sample of extant hominoids (12 species, 332 specimens), Old World (8 species, 43 specimens) and New World (4 species, 26 specimens) monkeys, fossil Miocene apes (8 species, 20 specimens) and Plio-Pleistocene hominins (8 species, 18 specimens).

RESULT

Results reveal a combination of parallel and synapomorphic morphology within haplorrhines, and especially within hominoids, across individual wrist bones. Similar morphology of some wrist bones reflects locomotor behaviour shared between clades (scaphoid, triquetrum and capitate) while others (lunate and hamate) indicate clade-specific synapomorphic morphology. Overall, hominoids show increased variation in wrist bone morphology compared with other primate clades, supporting previous analyses, and demonstrate several occurrences of parallel evolution, particularly between orangutans and hylobatids, and among hominines (extant African apes, humans and fossil hominins).

CONCLUSIONS

Our analyses indicate that different evolutionary processes can underlie the evolution of a single anatomical unit (the wrist) to produce diversity in functional and morphological adaptations across individual wrist bones. These results exemplify a degree of evolutionary and functional independence across different wrist bones, the potential evolvability of skeletal morphology, and help to contextualize the postcranial mosaicism observed in the hominin fossil record.

In vivo kinematics of the scaphoid, lunate, capitate, and third metacarpal in extreme wrist flexion and extension

PURPOSE

Insights into the complexity of active in vivo carpal motion have recently been gained using 3-dimensional imaging; however, kinematics during extremes of motion has not been elucidated. The purpose of this study was to determine motion of the carpus during extremes of wrist flexion and extension.

METHODS

We obtained computed tomography scans of 12 healthy wrists in neutral grip, extreme loaded flexion, and extreme loaded extension. We obtained 3-dimensional bone surfaces and 6-degree-of-freedom kinematics for the radius and carpals. The flexion and extension rotation from neutral grip to extreme flexion and extreme extension of the scaphoid and lunate was expressed as a percentage of capitate flexion and extension and then compared with previous studies of active wrist flexion and extension. We also tested the hypothesis that the capitate and third metacarpal function as a single rigid body. Finally, we used joint space metrics at the radiocarpal and midcarpal joints to describe arthrokinematics.

RESULTS

In extreme flexion, the scaphoid and lunate flexed 70% and 46% of the amount the capitate flexed, respectively. In extreme extension, the scaphoid extended 74% and the lunate extended 42% of the amount the capitates extended, respectively. The third metacarpal extended 4° farther than the capitate in extreme extension. The joint contact area decreased at the radiocarpal joint during extreme flexion. The radioscaphoid joint contact center moved onto the radial styloid and volar ridge of the radius in extreme flexion from a more proximal and ulnar location in neutral.

CONCLUSIONS

The contributions of the scaphoid and lunate to capitate rotation were approximately 25% less in extreme extension compared with wrist motion through an active range of motion. More than half the motion of the carpus when the wrist was loaded in extension occurred at the midcarpal joint.

CLINICAL RELEVANCE

These findings highlight the difference in kinematics of the carpus at the extremes of wrist motion, which occur during activities and injuries, and give insight into the possible etiologies of the scaphoid fractures, interosseous ligament injuries, and carpometacarpal bossing.

Elongation of the dorsal carpal ligaments: a computational study of in vivo carpal kinematics

PURPOSE

The dorsal radiocarpal (DRC) and dorsal intercarpal (DIC) ligaments play an important role in scapholunate and lunotriquetral stability. The purpose of this study was to compute changes in ligament elongation as a function of wrist position for the DRC and the scaphoid and trapezoidal insertions of the DIC.

METHODS

We developed a computational model that incorporated a digital dataset of ligament origin and insertions, bone surface models, and in vivo 3-dimensional kinematics (n = 28 wrists), as well as an algorithm for computing ligament fiber path.

RESULTS

The differences between the maximum length and minimum length of the DRC, DIC scaphoid component, and DIC trapezoidal component over the entire range of motion were 5.1 ± 1.5 mm, 2.7 ± 1.5 mm, and 5.9 ± 2.5 mm, respectively. The DRC elongated as the wrist moved from ulnar extension to radial flexion, and the DIC elongated as the wrist moved from radial deviation to ulnar deviation.

CONCLUSIONS

The DRC and DIC lengthened in opposing directions during wrist ulnar and radial deviation. Despite complex carpal bone anatomy and kinematics, computed fiber elongations were found to vary linearly with wrist position. Errors between computed values and model predictions were less than 2.0 mm across all subjects and positions.

CLINICAL RELEVANCE

The relationships between ligament elongation and wrist position should further our understanding of ligament function, provide insight into the potential effects of dorsal wrist incisions on specific wrist ranges of motion, and serve as a basis for modeling of the wrist.

Development and morphogenesis of human wrist joint during embryonic and early fetal period

The development of the human wrist joint has been studied widely, with the main focus on carpal chondrogenesis, ligaments and triangular fibrocartilage. However, there are some discrepancies concerning the origin and morphogenetic time-table of these structures, including nerves, muscles and vascular elements. For this study we used serial sections of 57 human embryonic (n = 30) and fetal (n = 27) specimens from O'Rahilly stages 17-23 and 9-14 weeks, respectively. The following phases in carpal morphogenesis have been established: undifferentiated mesenchyme (stage 17), condensated mesenchyme (stages 18 and 19), pre-chondrogenic (stages 19 and 20) and chondrogenic (stages 21 and over). Carpal chondrification and osteogenic processes are similar, starting with capitate and hamate (stage 19) and ending with pisiform (stage 22). In week 14, a vascular bud penetrates into the lunate cartilaginous mold, early sign of the osteogenic process that will be completed after birth. In stage 18, median, ulnar and radial nerves and thenar eminence appear in the hand plate. In stage 21, there are indications of the interosseous muscles, and in stage 22 flexor digitorum superficialis, flexor digitorum profundus and lumbrical muscles, transverse carpal ligament and collateral ligaments emerge. In stage 23, the articular disc, radiocarpal and ulnocarpal ligaments and deep palmar arterial arch become visible. Radiate carpal and interosseous ligaments appear in week 9, and in week 10, dorsal radiocarpal ligament and articular capsule are evident. Finally, synovial membrane is observed in week 13. We have performed a complete analysis of the morphogenesis of the structures of the human wrist joint. Our results present new data on nervous and arterial elements and provide the basis for further investigations on anatomical pathology, comparative morphology and evolutionary anthropology.

Methodological considerations for analyzing trabecular architecture: an example from the primate hand

Micro-computed tomographic analyses of trabecular bone architecture have been used to clarify the link between positional behavior and skeletal anatomy in primates. However, there are methodological decisions associated with quantifying and comparing trabecular anatomy across taxa that vary greatly in body size and morphology that can affect characterizations of trabecular architecture, such as choice of the volume of interest (VOI) size and location. The potential effects of these decisions may be amplified in small, irregular-shaped bones of the hands and feet that have more complex external morphology and more heterogeneous trabecular structure compared to, for example, the spherical epiphysis of the femoral head. In this study we investigate the effects of changes in VOI size and location on standard trabecular parameters in two bones of the hand, the capitate and third metacarpal, in a diverse sample of nonhuman primates that vary greatly in morphology, body mass and positional behavior. Results demonstrate that changes in VOI location and, to a lesser extent, changes in VOI size had a dramatic affect on many trabecular parameters, especially trabecular connectivity and structure (rods vs. plates), degree of anisotropy, and the primary orientation of the trabeculae. Although previous research has shown that some trabecular parameters are susceptible to slight variations in methodology (e.g. VOI location, scan resolution), this study provides a quantification of these effects in hand bones of a diverse sample of primates. An a priori understanding of the inherent biases created by the choice of VOI size and particularly location is critical to robust trabecular analysis and functional interpretation, especially in small bones with complex arthroses.

Carpal and forearm kinematics during a simulated hammering task

PURPOSE

Hammering is a functional task in which the wrist generally follows a path of motion from a position of combined radial deviation and extension to combined ulnar deviation and flexion, colloquially referred to as a dart thrower's motion. The purpose of this study was to measure wrist and forearm motion and scaphoid and lunate kinematics during a simulated hammering task. We hypothesized that the wrist follows an oblique path from radial extension to ulnar flexion and that there would be minimal radiocarpal motion during the hammering task.

METHODS

Thirteen healthy volunteers consented to have their wrist and distal forearm imaged with computed tomography at 5 positions while performing a simulated hammering task. The kinematics of the carpus and distal radioulnar joint were calculated using established markerless bone registration methods. The path of wrist motion was described relative to the sagittal plane. Forearm rotation and radioscaphoid and radiolunate motion were computed as a function of wrist position.

RESULTS

All volunteers performed the simulated hammering task using a path of wrist motion from radial extension to ulnar flexion that was oriented an average of 41 degrees +/- 3 degrees from the sagittal plane. These paths did not pass through the anatomic neutral wrist position; rather, they passed through a neutral hammering position, which was offset by 36 degrees +/- 8 degrees in extension. Rotations of the scaphoid and lunate were not minimal but averaged 40% and 41%, respectively, of total wrist motion. The range of forearm pronation-supination during the task averaged 12 degrees +/- 8 degrees .

CONCLUSIONS

The simulated hammering task was performed using a wrist motion that followed a coupled path of motion, from extension and radial deviation to flexion and ulnar deviation. Scaphoid and lunate rotations were greatly reduced, but not minimized, compared with rotations during pure wrist flexion/extension. This is likely because an extended wrist position was maintained throughout the entire task studied.

Conformational changes in the carpus during finger trap distraction

PURPOSE

Wrist distraction is a common treatment maneuver used clinically for the reduction of distal radial fractures and midcarpal dislocations. Wrist distraction is also required during wrist arthroscopy to access the radiocarpal joint and has been used as a test for scapholunate ligament injury. However, the effect of a distraction load on the normal wrist has not been well studied. The purpose of this study was to measure the three-dimensional conformational changes of the carpal bones in the normal wrist as a result of a static distractive load.

METHODS

Using computed tomography, the dominant wrists of 14 healthy volunteers were scanned at rest and during application of 98 N of distraction. Load was applied using finger traps, and volunteers were encouraged to relax their forearm muscles and to allow distraction of the wrist. The motions of the bones in the wrist were tracked between the unloaded and loaded trial using markerless bone registration. The average displacement vector of each bone relative to the radius was calculated, as were the interbone distances for 20 bone-bone interactions. Joint separation was estimated at the radiocarpal, midcarpal, and carpometacarpal joints in the direction of loading using the radius, lunate, capitate, and third metacarpal.

RESULTS

With loading, the distance between the radius and third metacarpal increased an average of 3.3 mm +/- 3.1 in the direction of loading. This separation was primarily in the axial direction at the radiocarpal (1.0 mm +/- 1.0) and midcarpal (2.0 mm +/- 1.7) joints. There were minimal changes in the transverse direction within the distal row, although the proximal row narrowed by 0.98 mm +/- 0.7. Distraction between the radius and scaphoid (2.5 mm +/- 2.2) was 2.4 times greater than that between the radius and lunate (1.0 mm +/- 1.0).

CONCLUSIONS

Carpal distraction has a significant (p < .01) effect on the conformation of the carpus, especially at the radiocarpal and midcarpal joints. In the normal wrist, external traction causes twice as much distraction at the lunocapitate joint than at the radiolunate joint.

Conservative management of symptomatic Carpal Bossing in an elite hockey player: a case report

OBJECTIVE

To present the characteristics and create awareness of symptomatic carpal bossing and discuss potential etiologies and the role of conservative management through the presentation of an athlete with traumatic onset of symptomatic carpal bossing.

CLINICAL FEATURES

This case report outlines the presentation and conservative management of an elite eighteen year old hockey player with symptomatic carpal bossing after a traumatic on ice collision. Carpal bossing is a bony, dorsal prominence in the quadrangular joint of the wrist that is inconsistently symptomatic.

INTERVENTION AND OUTCOME

A conservative treatment plan consisting of education, reassurance, avoidance of aggravation, and soft tissue therapy allowed return to play in two weeks without restrictions or need for surgical consultation.

CONCLUSION

With inconsistent recurrence rates and surgical complications, the role of conservative management for symptomatic carpal bossing deserves further exploration. The conservative practitioner should be aware of the signs and symptoms of symptomatic carpal bossing to institute suitable treatment.

"Twist of the wrist" a rare case of carpal dislocation

A rare case of a scaphoid-trapezium dislocation is presented. The treatment was open reduction, ligament repair, and internal fixation with a Kirschner wire. After 4 weeks of immobilization, the Kirschner wire was removed, and full recovery was obtained 12 weeks after the trauma.

Rare isolated trapezoid fracture: a case report

Isolated fractures of the trapezoid are rare. Of all of the fractures of the carpus, the most common is the scaphoid, which represents 68.2% of all carpal fractures (Papp, Orthop Clin N Am 38:251-60, 2007). In contrast, trapezoid fractures represent 0.4% of all carpal injuries. Because it is an infrequently fractured carpal bone, there is a wide variety of treatment plans, including rest, immobilization, and surgery (Green and Pederson, Green's Operative Hand Surgery, Elsevier, Philadelphia, 759 pp, 2005). In this report, we describe a patient who presented with an isolated fracture of the trapezoid that was successfully treated with cast immobilization and had a full functional recovery.