The carpal stretch test

Objective

To compare the sensitivity of traditional motion studies, bone scintigraphy and radiocarpal arthrography to a “carpal stretch test,” for evaluation of dynamic dissociative carpal instability.

Design

Experimental study comparing the results of the tests to the findings of arthroscopy, the “gold standard.”

Setting

A university hospital-based upper extremity practice.

Patients

Six patients with chronic wrist pain, arthroscopically confirmed proximal row ligamentous disruption and radiographs not suggestive of proximal row instability.

Interventions

The carpal stretch test: both affected and unaffected wrists were subjected to the same testing, wherein the wrist was suspended from finger traps for 10 minutes by a 4.5-kg weight. Standardized posteroanterior radiographs were taken of the suspended wrists.

Main outcome measures

Disruption of Gilula’s arcs I and II, and sensitivity of the carpal stretch test compared with other investigations.

Main results

Step deformities ranging from 2.5 to 6 mm (average 3.7 mm) were recorded in the affected wrists and 0 to 4 mm (average 1.5 mm) in the “unaffected” wrists. The test was more sensitive than traditional radiography, arthrography and scintigraphy in defining both presence and site of proximal carpal row ligamentous tears and was almost as sensitive as arthroscopy.

Conclusion

In patients with chronic wrist pain and dynamic dissociative wrist instability, the carpal stretch test may prove to be a valuable screening tool for detecting ligamentous tears of the proximal carpal row.     

Tenosynovitis of the wrist and thumb and carpal tunnel syndrome caused by Histoplasma capsulatum: case report and review of the literature

A patient presenting with acute carpal tunnel syndrome and swelling and pain in the wrist and thumb is presented. An open carpal tunnel release and tenosynovectomy were performed with biopsy specimen revealing infection with Histoplasma capsulatum. The case is discussed in context of the prior scant literature of tenosynovitis of the wrist and hand caused by histoplasmosis.     

The aetiology and current management of prepubertal epididymitis

Introduction

The aim of this study was to review the published evidence on the pathogenesis and management of acute epididymitis (AE) in prepubertal boys after the authors encountered an unexpectedly large number of such cases in their institution.

Methods

Using MEDLINE^®, a literature search was performed for articles in English with the words “pre-pubertal” OR “boys” OR “p(a)ediatric” OR “children” AND “epididymitis” OR “epididymo-orchitis”.

Results

The literature suggests that it is rare to find a bacterial infection or anatomical anomaly as a cause for AE in this population. A postviral infectious phenomenon is the most likely explanation. The management should be supportive and antibiotics reserved for those with pyuria or positive cultures. Urodynamic studies and renal tract ultrasonography have been advocated for those with recurrent epididymitis.

Conclusions

AE in prepubertal boys is more common than believed previously. A careful history for recent viral illnesses should be included. Antibiotics, urinary tract imaging and functional studies should be used in selected cases.     

Dorsal Wrist Extrinsic Carpal Ligament Injury Exacerbates Volar Radiocarpal Instability After Intra-Articular Distal Radius Fracture

Background: Volar radiocarpal instability is often seen after loss of fixation of volar lunate facet fragments. The pathogenesis of post-traumatic volar radiocarpal instability is poorly understood. The purpose of this study was to determine if injury to the dorsal wrist extrinsic carpal ligaments contributes to volar radiocarpal instability. Methods: Six matched pairs of cadaveric upper extremities were tested using a dynamic hand testing system. In group 1, the intact wrist, the wrist with a volar lunate facet fracture, and the fractured wrist after 500 cycles of grip were tested. In group 2, in addition to the intact and fractured wrist, the fractured wrist with the dorsal extrinsic carpal ligaments cut and the fractured wrist with the dorsal extrinsic carpal ligaments cut after 500 cycles of grip were also tested. Volar-dorsal displacement of the lunate was measured from 45° wrist flexion to 45° wrist extension in 22.5° increments with the wrist flexors/extensors loaded for each condition. Results: Volar lunate translation did not significantly increase after the volar lunate facet fracture alone, and was not evident to a significant extent until the dorsal wrist extrinsic carpal ligaments were cut. Further instability of the lunate occurred after grip cycling only with the dorsal extrinsic capsular ligaments cut. Conclusions: Injury to the dorsal wrist extrinsic carpal ligaments exacerbates volar radiocarpal instability. Unrecognized dorsal sided injury may be a contributing factor to why stable fixation of volar lunate facet fragments remains problematic after volar plating of intra-articular distal radius fractures with displaced volar lunate facet fragments.     

Cervical and mediastinal abscess as a manifestation of histoplasmosis

Histoplasmosis is the most common endemic respiratory mycosis in the United States. Disseminated histoplasmosis generally is initially seen with systemic or respiratory complaints. Presentation of histoplasmosis as a neck mass is rare. Due to this unusual presentation and the diagnostic implications, we present a case of disseminated histoplasmosis that presented as a neck abscess. Unusual presentations of histoplasmosis may occur even in patients who are not immunocompromised. The diagnosis and management of histoplasmosis is reviewed. Histoplasmosis should be considered in the workup of a cervical abscess even in the immunocompetent host.     

Hand Transplantation—Risks and Benefits

Composite tissue allotransplantation (CTA) is the culmination of progress in transplantation, allowing the reconstruction of the hand in amputees. Worldwide, more than 100 procedures have been performed. The aim of this work was to understand the hand allotransplantation approach, making known current aspects, risks, and benefits. A PubMed research was realized between October 2018 and March 2019, including terms like “Hand transplantation” AND “Composite tissue allotransplantation,” “Hand transplantation” AND “Functional outcomes,” “Hand transplantation” AND “Immunosuppression,” “Hand prosthetics,” “Hand Transplantation” AND “Ethics.” There were included papers between 1995 and 2018, with English language, amputee human adults, systematic reviews, and clinical studies. Seventy-two papers were fully evaluated. There are technical aspects that influence the procedure like team coordination or surgical technique. It requires a long-life treatment, which has risks such as toxicity or infections. However, it allows the recovery of fine movements, and independence, to perform detailed tasks. The indications must be carefully considered, because some patients benefit from the use of prosthesis. CTA has become an option for amputees so it is important to do more research, to determine the benefits of this procedure. It is not considered a life-saving procedure, so there is an ethical debate because of the risks.     

The internet as a source of information for De Quervain’s tendinitis

Background

Many individuals are turning to the Internet for information about various health conditions, and in our study we evaluated the quality and readability of information on the internet about De Quervain’s tendinitis.

Methods

We chose the search terms “De Quervain’s Tendinitis,” “De Quervain’s Tenosynovitis,” and “De Quervain’s Syndrome,” and entered them into the search engines “Google,” “Bing,” and “Yahoo” and compiled the search results. The websites were then evaluated and assigned a quality score, a Flesch-Kincaid (FK) reading level, and a subjective quality score. They were then grouped according to the search term used, search engine used, and the order (priority) returned by the search engines. ANOVA analysis and pairwise comparisons of quality and readability among groups, as well as correlation analysis were performed.

Results

The FK readability average was 10.3, above the recommended level. The search term De Quervain’s tenosynovitis returned the highest objective quality results. There was no statistical difference found between the different search engines. The first 10 results from the searches were of higher quality than results 11–20, and there was a positive correlation between objective and subjective quality scores but no correlation between readability and objective quality.

Conclusions

We concluded that quality information about De Quervain’s tendinitis is available on the internet and is most likely to be found using the search term De Quervain’s tenosynovitis and in the first 10 results of an internet search. However, most information is written above the recommended 6th grade reading level.     

Medically managed gout precipitating acute carpal tunnel syndrome

Background

The most common compressive neuropathy affects the median nerve in the carpal tunnel; it is typically chronic and progressive. Acute carpal tunnel syndrome (ACTS), on the other hand, is a less frequently encountered surgical emergency that usually occurs in the setting of trauma, such as a displaced fracture of the distal radius or carpal dislocation. To our knowledge, there are only two cases of acute carpal tunnel secondary to gout reported in the literature, with both being outside of the USA and the last case being over 20 years ago. We reviewed the literature describing acute carpal tunnel syndrome (ACTS) caused by gout and present a recent case of atraumatic ACTS caused, in part, by a tophaceous gouty mass.

Methods

Review of the literature consisted of a PubMed search of all articles in the English language using the following keywords: “Acute Carpal Tunnel Syndrome” and “Tophaceous Gout” and “Gout.”

Results

We present the youngest reported case of atraumatic ACTS caused by tophaceous gout and the only reported case with a documented history of gout being actively medically managed with a uric acid lowering agent. This was successfully treated with an emergent extended carpal tunnel release, a complete flexor synovectomy, and excision of a gouty mass adhered to the carpal tunnel floor.

Conclusions

Atraumatic ACTS secondary to gout is rare and has never been reported in a patient already being managed with uric acid lowering agents. Such a presentation requires rapid surgical exploration with release of the carpal tunnel, debridement of all gouty tissue, and increasingly aggressive adjuvant medical therapy.     

Use of safety scalpels and other safety practices to reduce sharps injury in the operating room: What is the evidence?

Background

The occupational hazard associated with percutaneous injury in the operating room (OR) has encouraged harm reduction through behaviour change and the use of safety-engineered surgical sharps. Some Canadian regulatory agencies have mandated the use of “safety scalpels.” Our primary objective was to determine whether safety scalpels reduce the risk of percutaneous injury in the OR, while a secondary objective was to evaluate risk reduction associated with other safety practices.

Methods

We used evidence review methods described by the International Liaison Committee on Resuscitation and conducted a systematic, English-language search of Ovid, MEDLINE and EMBASE using the following search terms: “safety-engineered scalpel,” “mistake proofing device,” “retractable/removable blade/scalpel,” “pass tray,” “hands free passing,” “neutral zone,” “sharpless surgery,” “double/cutproof gloving” and “blunt suture needles.” Included articles were scored according to level of evidence; quality; and whether they were supportive, opposed or neutral to the study question(s).

Results

Of 72 included citations, none was supportive of the use of safety scalpels. There was high-level/quality evidence (Cochrane reviews) in support of risk reduction through double-gloving and use of blunt suture needles, with additional evidence supporting a pass tray/neutral zone for sharps handling (4 of 5 articles supportive) and use of suturing adjuncts (1 article supportive).

Conclusion

There is insufficient evidence to support regulated use of safety scalpels. Injury-reduction strategies should emphasize proven methods, including double-gloving, blunt suture needles and use of hands-free sharps transfer.     

Risk of Adverse Pregnancy Outcomes in Women with CKD

CKD is increasingly prevalent in pregnancy. In the Torino-Cagliari Observational Study (TOCOS), we assessed whether the risk for adverse pregnancy outcomes is associated with CKD by comparing pregnancy outcomes of 504 pregnancies in women with CKD to outcomes of 836 low-risk pregnancies in women without CKD. The presence of hypertension, proteinuria (>1 g/d), systemic disease, and CKD stage (at referral) were assessed at baseline. The following outcomes were studied: cesarean section, preterm delivery, and early preterm delivery; small for gestational age (SGA); need for neonatal intensive care unit (NICU); new onset of hypertension; new onset/doubling of proteinuria; CKD stage shift; “general” combined outcome (preterm delivery, NICU, SGA); and “severe” combined outcome (early preterm delivery, NICU, SGA). The risk for adverse outcomes increased across stages (for stage 1 versus stages 4–5: “general” combined outcome, 34.1% versus 90.0%; “severe” combined outcome, 21.4% versus 80.0%; P<0.001). In women with stage 1 CKD, preterm delivery was associated with baseline hypertension (odds ratio [OR], 3.42; 95% confidence interval [95% CI], 1.87 to 6.21), systemic disease (OR, 3.13; 95% CI, 1.51 to 6.50), and proteinuria (OR, 3.69; 95% CI, 1.63 to 8.36). However, stage 1 CKD remained associated with adverse pregnancy outcomes (general combined outcome) in women without baseline hypertension, proteinuria, or systemic disease (OR, 1.88; 95% CI, 1.27 to 2.79). The risk of intrauterine death did not differ between patients and controls. Findings from this prospective study suggest a “baseline risk” for adverse pregnancy-related outcomes linked to CKD.     

Current updates in management of extremity injuries in polytrauma

Injury-related morbidity and mortality have been one of the most common causes of loss in productivity across all geographic distributions. It remains to be a global concern despite a continual improvement in regional and national safety policies. The establishment of trauma care systems and advancements in diagnostics and management have improved the overall survival of severely injured. A better understanding of the physiopathological and immunological responses to injury led to a significant shift in trauma care from “Early Total Care” to “Damage Control Orthopedics.” While most of these algorithms were tailored to the philosophy of “life before limb,” the impact of improper fracture management on disability and societal loss is increasingly being recognized. Recently, “Early Appropriate Care” of extremities has gained importance; however, its implementation is influenced by regional health care policies, available resources, and expertise and varies between low and high-income countries. A review of the literature was performed using PubMed, Embase, Web of Science, and Scopus databases on articles published from 1990 to 2020 using the Mesh terms “Polytrauma,” “Multiple Trauma,” and “Fractures.” This review aims to consolidate on guidelines and available evidence in the management of extremity injuries in a polytraumatized patient to achieve better clinical outcomes of these severely injured.     

Impact of osteoporosis in dental implants: A systematic review

AIM: To assess the failure and bone-to-implant contact rate of dental implants placed on osteoporotic subjects.METHODS: Extensive examination strategies were created to classify studies for this systematic review. MEDLINE (via PubMed) and EMBASE database were examined for studies in English up to and including May 2014. The examination presented a combination of the MeSH words described as follow: “osteoporosis” or “osteopenia” or “estrogen deficiency” AND “implant” or “dental implant” or “osseointegration”. Assessment of clinical and/or histological peri-implant conditions in osteoporosis subjects treated with titanium dental implants. The examination included a combination of the MeSH terms described as follow: “osteoporosis” or “osteopenia” or “estrogen deficiency” AND “implant” or “dental implant” or “osseointegration”.RESULTS: Of 943 potentially eligible articles, 12 were included in the study. A total of 133 subjects with osteoporosis, 73 subjects diagnosed with osteopenia and 708 healthy subjects were assessed in this systematic review. In these subjects were installed 367, 205, 2981 dental implants in osteoporotic, osteopenic and healthy subjects, respectively. The failure rate of dental implant was 10.9% in osteoporotic subjects, 8.29% in osteopenic and 11.43% in healthy ones. Bone-to-implant contact obtained from retrieved implants ranged between 49.96% to 47.84%, for osteoporosis and non-osteoporotic subjects.CONCLUSION: Osteoporotic subjects presented higher rates of implant loss, however, there is a lower evidence to strengthen or refute the hypothesis that osteoporosis may have detrimental effects on bone healing. Consequently, final conclusions regarding the effect of osteoporosis in dental implant therapy cannot be made at this time. There are no randomized clinical trial accessible for evaluation and the retrospective nature of the evaluated studies shall be taken in account when interpreting this study.     

Carpal kinematics during simulated active and passive motion of the wrist

PURPOSE: The purpose of this study was to investigate the effect of experimental control mechanisms, simulated active (tendon-driven) and passive (externally assisted), on carpal motion. METHODS: Kinematics of the carpal bones in five fresh-frozen cadaver upper extremities were studied using an optical motion analysis system. The wrist extensors and flexors were dissected and loaded. For passive motion, the tendons were loaded to simulate muscle tone while the investigator passively moved the wrist using a pin placed in the third metacarpal. To simulate active, patient-driven motion, the tendons were attached directly to guide bars while the investigator used a puppeteer mechanism to move the wrist. RESULTS: There were no significant differences in carpal motion (flexion-extension motion or radial-ulnar deviation) when the wrist was moved in simulated active motion through the extensor and flexor tendons or in passive motion, with a constant force applied to the tendons. Kinematics for simulated active motion, in general, was more difficult to control and was less smooth than the kinematics for passive motion. CONCLUSIONS: Carpal bone kinematics (excluding the pisiform) in a healthy normal joint are similar in both simulated active (tendon-driven) and passive (externally assisted) wrist motion because the carpal bones are passively moved during wrist motion (there are no direct tendon-to-muscle attachments to the proximal carpal bones and minimal attachments to the distal carpal bones).     

Hazards of steroid injection: Suppurative extensor tendon rupture

Local steroid injections are often administered in the office setting for treatment of trigger finger, carpal tunnel syndrome, de Quervain''s tenosynovitis, and basal joint arthritis. If attention is paid to sterile technique, infectious complications are rare. We present a case of suppurative extensor tenosynovitis arising after local steroid injection for vague symptoms of dorsal hand and wrist pain. The progression of signs and symptoms following injection suggests a natural history involving bacterial superinfection leading to tendon rupture. We discuss the pitfalls of local steroid injection and the appropriate management of infectious extensor tenosynovitis arising in such situations.     

Evaluation of preoperative and perioperative operating room briefings at the Hospital for Sick Children

Background

Wrong-site, wrong-procedure and wrong-patient surgeries are catastrophic events for patients, medical caregivers and institutions. Operating room (OR) briefings are intended to reduce the risk of wrong-site surgeries and promote collaboration among OR personnel. The purpose of our study was to evaluate 2 OR briefing safety initiatives, “07:35 huddles” (preoperative OR briefing) and “surgical time-outs” (perioperative OR briefing), at the Hospital for Sick Children in Toronto, Ont.

Methods

First, we evaluated the completion and components of the 07:35 huddles and surgical time-outs briefings using direct observations. We then evaluated the attitudes of the OR staff regarding safety in the OR using the “Safety Attitudes Questionnaire, Operating Room version.” Finally, we conducted personal interviews with OR personnel.

Results

Based on direct observations, 102 of 159 (64.1%) 07:35 huddles and 230 of 232 (99.1%) surgical time-outs briefings were completed. The perception of safety in the OR improved, but only among nurses. Regarding difficulty discussing errors in the OR, the nurses’ mean scores improved from 3.5 (95% confidence interval [CI] 3.2–3.8) prebriefing to 2.8 (95% CI 2.5–3.2) postbriefing on a 5-point Likert scale (p < 0.05). Personal interviews confirmed that, mainly among the nursing staff, pre-and perioperative briefing tools increase the perception of communication within the OR, such that discussions regarding errors within the OR are more encouraged.

Conclusion

Structured communication tools, such as 07:35 huddles and surgical time-outs briefings, especially for the nursing personnel, change the notion of individual advocacy to one of teamwork and being proactive about patient safety.     

Hand Corticosteroid Injections in Patients on “Blood Thinners”

Background: Our study aims to identify any influence that anticoagulation and antiplatelet (“blood thinner”) medications have on hand and wrist corticosteroid injection complication rates. Methods: This retrospective chart review looked at patients between the ages of 18 and 89 years who received corticosteroid injections in the hand or wrist between 2013 and 2017, noting anticoagulation and antiplatelet use, demographics, injection placement, and surgical intervention. Results: Only 152 (20.9%) of the 726 diagnoses that were treated needed eventual surgical intervention. There were 12 overall reported complications after 1473 injections (0.8%). There were 6 complications after 433 injections (1.6%) placed in patients on blood thinners and 6 complications after 1040 injections (0.6%) placed in patients not on blood thinners. Conclusions: With the complication rate of corticosteroid injections being so low, even in patients taking “blood thinners,” the fear of adverse reactions should not preclude a physician from using this treatment modality to prevent surgical intervention.     

Women of Worth: the impact of a cash plus intervention to enhance attendance and reduce sexual health risks for young women in Cape Town,South Africa

IntroductionConditional cash transfers (CTs) augmented with other interventions are promising interventions for reducing HIV risk in adolescent girls and young women.MethodsA multi‐phase, quasi‐experimental study assessed the impact of a CT (ZAR300; $22) conditional on attending a skills building intervention, Women of Worth (WoW), designed to improve sexual and reproductive health (SRH) outcomes in Cape Town, South Africa from May 2017 to December 2019. The intervention entailed 12 sessions with encouragement to attend adolescent and youth‐friendly health services. Women aged 19–24 years were randomized 1:1 to receive the intervention with a CT (“cash + care” or C+C) or without a CT (“care”). The study included a pilot phase followed by a post‐modification phase with improved uptake and retention without changing programme content or CT. Self‐reported HIV prevalence and SRH/HIV vulnerability were assessed via a self‐administered questionnaire at baseline, after 11 sessions, and 6–30 months’ post‐intervention for a subset. Mixed effect logistic regression models were fitted to estimate within‐subject changes in outcomes.ResultsOf 5116 participants, 904 (452 participants per arm) were in the pilot and 4212 (2039 “care” participants and 2173 “C+C” participants) were in the post modified phase. There were 1867 (85.9%) and 135 (6,6%) participants in the “C+C” group and the “Care,” respectively, that were WoW completers (≥ 11 sessions/retention). During the pilot phase, 194 (42.9%) and 18 (4.0%) participants in “C+C” and the “care” groups were retained. Receiving a CT sustained participation nearly 60‐fold (OR 60.37; 95% CI: 17.32; 210.50, p <0.001). Three‐hundred and thirty women were followed for a median of 15.0 months [IQR: 13.3; 17.8] to assess the durability of impact. Self‐reported new employment status increased more than three‐fold (p <0.001) at WoW completion and was sustained to the longer time point. Intimate partner violence indicators were reduced immediately after WoW, but this was not durable.ConclusionsParticipants receiving CT had sustained participation in an SRH/HIV prevention skills building with improvement in employment and some SRH outcomes. Layered, “young woman centred” programmes to address HIV and SRH risk in young women may be enhanced with CT.     

Mobilization with movement as an adjunct intervention in a patient with complicated de Quervain's tenosynovitis: a case report

STUDY DESIGN: Case study. OBJECTIVES: To describe the use of conventional physical therapy interventions together with Mobilization With Movement (MWM) techniques in the treatment of an individual with a complicated scenario of de Quervain's tenosynovitis. BACKGROUND: The patient was a 61-year-old woman who presented with signs and symptoms consistent with de Quervain's tenosynovitis of the right hand. Range limitations in all motions of the right wrist and first carpometacarpal joint complicated her presentation. METHODS AND MEASURES: Physical therapy included conventional intervention with superficial heat, ice, iontophoresis, and transverse friction massage directed to the first dorsal tunnel. Conventional joint mobilization techniques addressed the motion limitations of the first carpometacarpal, radiocarpal, and midcarpal joints. In addition, MWM techniques were utilized to promote pain-free wrist and thumb mobility. The specific MWM techniques used with this patient involved active movements of the thumb and wrist superimposed on a passive radial glide of the proximal row of carpal bones. RESULTS: The described treatment regime, which involved conventional physical therapy interventions, along with MWM, aided in the complete resolution of this patient's impairments and functional limitations. CONCLUSION: The combination of conventional physical agents, exercise, and manual therapy, and the less conventional MWM techniques, proved successful with this patient. MWM involving the correction of minutejoint malalignments, coupled with active motion of the wrist and first carpometacarpal joints, was an effective and efficient adjunct physical therapy intervention. Because subtle changes injoint alignment may contribute to painful syndromes in the tendon complexes that cross a malaligned joint, use of MWM as a treatment technique warrants continued research.     

Clinical Case of Acute Non-Traumatic Hand Compartment Syndrome and Systematic Review for the Upper Extremity

Background: While trauma to the upper extremity is known to cause acute compartment syndrome (ACS), nontraumatic causes of ACS of the upper extremity are rare. Nontraumatic ACS of the upper extremity can lead to adverse outcomes if not recognized early. There are limited reports of spontaneous ACS published in the literature. The aim of this comprehensive systematic review is to increase awareness among plastic surgeons and hand surgeons of this acute event and provide an algorithmic approach to management in the acute setting through an illustrative case example. Methods: A comprehensive systematic review of published literature was conducted in the Medline/PubMed database with the search terms, “compartment syndrome,” “extremity,” “spontaneous,” “nontraumatic,” and “atraumatic” without timeframe limitations. Articles were identified and included in this review based on ACS localization in the upper extremity and etiology of nontraumatic, spontaneous origin. Results: Sixteen publications and 19 total cases of nontraumatic ACS of the upper extremity from 1993 to 2016 met our search criteria. A bleeding disorder was the etiology in three cases, systemic anticoagulation in three cases, infection in six cases, and unknown in three cases. The remaining four cases included systemic sclerosis, Ehlers-Danlos syndrome, rhabdomyolysis, and McArdle disease. Conclusions: Nontraumatic causes of ACS of the upper extremity include infection, anticoagulation therapy, and bleeding disorders. Even though trauma is the most common cause of ACS, clinicians should be aware of these other potential causes of ACS in the nontraumatic setting. Appropriate medical and surgical intervention should be done to avoid potential adverse outcomes.     

Biomechanical changes of the wrist flexor and extensor tendons following loss of scaphoid integrity

Loss of integrity of the scaphoid may change the motion center of the entire carpus, and deformities from scaphoid fractures may alter the location of motor tendons of the wrist, thus altering their biomechanics. The goal of this study was to clarify biomechanical changes in these tendons following loss of scaphoid integrity. Excursions and moment arms of the principal flexor and extensor tendons of the wrist were investigated in seven cadaveric upper extremities in intact wrists after simulation of scaphoid waist fracture and after removal of the proximal scaphoid. Excursions of the flexor carpi radialis and ulnaris extensor carpi radialis longus and brevis, and extensor carpi ulnaris tendons were measured with rotary potentiometers during wrist flexion-extension and radioulnar deviation. Simultaneously, wrist joint angulation was recorded. Moment arms of the tendons were derived from tendon excursions and joint motion. After scaphoid fracture, the moment arms of the flexor carpi radialis and extensor carpi ulnaris tendons increased significantly during wrist flexion-extension, whereas the moment arms of the extensor carpi radialis longus and brevis tendons decreased significantly. After proximal scaphoid excision, the moment arms of the extensor carpi radialis longus and brevis tendons again decreased significantly during wrist flexion-extension. The moment arms of the flexor carpi radialis and extensor carpi radialis brevis tendons increased significantly during radioulnar deviation, whereas those of the wrist motors on the ulnar side decreased. These findings indicate the importance of the integrity of the scaphoid in maintaining normal biomechanics of motor tendons of the wrist. An increase in the moment arm of the radial wrist flexor along with a decrease in moment arms of the radial extensors constitutes an etiology for persistent angulation of the scaphoid and the hump-back deformity. In addition, disturbing the biomechanics of the wrist motor tendons predisposes the carpal joints to abnormal loading, potentially contributing to the development of carpal joint degeneration.