A review of wear debris in thumb base joint implants.

AIM: Polymers and metals, such as polyethylene (PE) and cobalt chrome (CoCr), are common materials used in thumb-based joint implants, also known as CMC (Carpometacarpal) arthroplasty. The purpose of this review was to investigate the reported failure modes related to wear debris from these type of materials in CMC implants. The impact of wear debris on clinical outcomes of CMC implants was also examined. Potential adverse wear conditions and inflammatory particle characteristics were also considered. METHOD: A literature search was performed using PRISMA guidelines and 55 studies were reviewed including 49 cohort studies and 6 case studies. Of the 55 studies, 38/55 (69%) focused on metal-on-polyethylene devices, followed by metal-on-metal (35%), and metal-on-bone (4%). RESULTS: The summarized data was used to determine the frequency of failure modes potentially related to wear debris from metals and/or polymers. The most commonly reported incidents potentially relating to debris were implant loosening (7.1%), osteolysis (1.2%) and metallosis (0.6%). Interestingly the reported mechanisms behind osteolysis and loosening greatly varied. Inflammatory reactions, while rare, were generally attributed to metallic debris from metal-on-metal devices. Mechanisms of adverse wear conditions included implant malpositioning, over-tensioning, high loading for active patients, third-body debris, and polyethylene wear-through. No specific examination of debris particle characterization was found, pointing to a gap in the literature. CONCLUSION: This review underscores the types of failure modes associated with wear debris in CMC implants. It was found that failure rates and adverse wear conditions of CMC implants of any design are low and the exact relationship between wear debris and implant incidences, such as osteolysis and loosening remains uncertain. The authors note that further research and specific characterization is required to understand the relationship between debris and implant failure.

Dorsal Subluxation of the First Metacarpal During Thumb Flexion is an Indicator of Carpometacarpal Osteoarthritis Progression.

BACKGROUND: Measurable changes in patients with progression of thumb carpometacarpal (CMC) osteoarthritis (OA) include joint space narrowing, osteophyte formation, subluxation, and adjacent-tissue changes. Subluxation, an indication of mechanical instability, is postulated as an early biomechanical indicator of progressing CMC OA. Various radiographic views and hand postures have been proposed to best assess CMC subluxation, but 3D measurements derived from CT images serve as the optimal metric. However, we do not know which thumb pose yields subluxation that most indicates OA progression. QUESTIONS/PURPOSES: Using osteophyte volume as a quantitative measure of OA progression, we asked: (1) Does dorsal subluxation vary by thumb pose, time, and disease severity in patients with thumb CMC OA? (2) In which thumb pose(s) does dorsal subluxation most differentiate patients with stable CMC OA from those with progressing CMC OA? (3) In those poses, what values of dorsal subluxation indicate a high likelihood of CMC OA progression? METHODS: Between 2011 and 2014, 743 patients were seen at our institutions for trapeziometacarpal pain. We considered individuals who were between the ages of 45 and 75 years, had tenderness to palpation or a positive grind test result, and had modified Eaton Stage 0 or 1 radiographic thumb CMC OA as potentially eligible for enrollment. Based on these criteria, 109 patients were eligible. Of the eligible patients, 19 were excluded because of a lack of interest in study participation, and another four were lost before the minimum study follow-up or had incomplete datasets, leaving 86 (43 female patients with a mean age of 53 ± 6 years and 43 male patients with a mean age of 60 ± 7 years) patients for analysis. Twenty-five asymptomatic participants (controls) aged 45 to 75 years were also prospectively recruited to participate in this study. Inclusion criteria for controls included an absence of thumb pain and no evidence of CMC OA during clinical examination. Of the 25 recruited controls, three were lost to follow-up, leaving 22 for analysis (13 female patients with a mean age of 55 ± 7 years and nine male patients with a mean age of 58 ± 9 years). Over the 6-year study period, CT images were acquired of patients and controls in 11 thumb poses: neutral, adduction, abduction, flexion, extension, grasp, jar, pinch, grasp loaded, jar loaded, and pinch loaded. CT images were acquired at enrollment (Year 0) and Years 1.5, 3, 4.5, and 6 for patients and at Years 0 and 6 for controls. From the CT images, bone models of the first metacarpal (MC1) and trapezium were segmented, and coordinate systems were calculated from their CMC articular surfaces. The volar-dorsal location of the MC1 relative to the trapezium was computed and normalized for bone size. Patients were categorized into stable OA and progressing OA subgroups based on trapezial osteophyte volume. MC1 volar-dorsal location was analyzed by thumb pose, time, and disease severity using linear mixed-effects models. Data are reported as the mean and 95% confidence interval. Differences in volar-dorsal location at enrollment and rate of migration during the study were analyzed for each thumb pose by group (control, stable OA, and progressing OA). A receiver operating characteristic curve analysis of MC1 location was used to identify thumb poses that differentiated patients whose OA was stable from those whose OA was progressing. The Youden J statistic was used to determine optimized cutoff values of subluxation from those poses to be tested as indicators of OA progression. Sensitivity, specificity, negative predictive values, and positive predictive values were calculated to assess the performance of pose-specific cutoff values of MC1 locations as indicators of progressing OA. RESULTS: In flexion, the MC1 locations were volar to the joint center in patients with stable OA (mean -6.2% [95% CI -8.8% to -3.6%]) and controls (mean -6.1% [95% CI -8.9% to -3.2%]), while patients with progressing OA exhibited dorsal subluxation (mean 5.0% [95% CI 1.3% to 8.6%]; p < 0.001). The pose associated with the most rapid MC1 dorsal subluxation in the progressing OA group was thumb flexion (mean 3.2% [95% CI 2.5% to 3.9%] increase per year). In contrast, the MC1 migrated dorsally much slower in the stable OA group (p < 0.001), at only a mean of 0.1% (95% CI -0.4% to 0.6%) per year. A cutoff value of 1.5% for the volar MC1 position during flexion at enrollment (C-statistic: 0.70) was a moderate indicator of OA progression, with a high positive predictive value (0.80) but low negative predictive value (0.54). Positive and negative predictive values of subluxation rate in flexion (2.1% per year) were high (0.81 and 0.81, respectively). The metric that most indicated a high likelihood of OA progression (sensitivity 0.96, negative predictive value 0.89) was a dual cutoff that combined the subluxation rate in flexion (2.1% per year) with that of loaded pinch (1.2% per year). CONCLUSION: In the thumb flexion pose, only the progressing OA group exhibited MC1 dorsal subluxation. The MC1 location cutoff value for progression in flexion was 1.5% volar to the trapezium , which suggests that dorsal subluxation of any amount in this pose indicates a high likelihood of thumb CMC OA progression. However, volar MC1 location in flexion alone was not sufficient to rule out progression. The availability of longitudinal data improved our ability to identify patients whose disease will likely remain stable. In patients whose MC1 location during flexion changed < 2.1% per year and whose MC1 location during pinch loading changed < 1.2% per year, the confidence that their disease would remain stable throughout the 6-year study period was very high. These cutoff rates were a lower limit, and any patients whose dorsal subluxation advanced faster than 2% to 1% per year in their respective hand poses, were highly likely to experience progressive disease. CLINICAL RELEVANCE: Our findings suggest that in patients with early signs of CMC OA, nonoperative interventions aimed to reduce further dorsal subluxation or operative treatments that spare the trapezium and limit subluxation may be effective. It remains to be determined whether our subluxation metrics can be rigorously computed from more widely available technologies, such as plain radiography or ultrasound.

Radiocarpal Fusion: Indications, Technique, and Modifications.

Degenerative disorders of the wrist may affect isolated joints and inhibit normal functions of the wrist secondary to pain and stiffness. These processes that affect only the radiocarpal joint may be secondary to posttraumatic osteoarthritis, primary osteoarthritis, or rheumatoid arthritis. Radiocarpal wrist arthrodesis may help preserve some of the native wrist kinematics while alleviating pain and improving the range of motion. However, the surgeon must ensure that the patient's pathologic process primarily affects the radiocarpal articulations while relatively sparing the midcarpal articulations. Depending on the location of the pathology, isolated radiolunate or radioscapholunate arthrodesis have been described to preserve some motion in the midcarpal joint. To maximize motion in the midcarpal joint after radiocarpal arthrodesis, techniques for distal scaphoid and triquetrum excision have been described. We report patient outcomes for various techniques and describe our preferred technique for radioscapholunate arthrodesis using distal scaphoid excision.

Evaluation of the PROMIS Upper Extremity Against Validated Patient-Reported Outcomes in Patients With Early Carpometacarpal Osteoarthritis.

PURPOSE: Internal consistency, construct, and criterion validity of the Patient-Reported Outcomes Measurement Information System (PROMIS) upper extremity (UE) v1.2 were evaluated in patients with early-stage carpometacarpal (CMC) osteoarthritis (OA). We hypothesized that in patients with early CMC OA, PROMIS UE scores would: (1) be lower than those in asymptomatic controls; (2) correlate with established patient-reported outcomes; (3) correlate with pinch and grip strengths; and (4) not correlate with radiographic disease progression. METHODS: Patients with early CMC OA (modified Eaton stage 0 or 1) and matched asymptomatic control patients completed the PROMIS UE, Australian and Canadian Osteoarthritis Hand Index, and Patient-Rated Wrist-Hand Evaluation at 2 time points. The PROMIS UE's internal consistency was evaluated by Cronbach's alpha, construct validity by Spearman correlation coefficients among the patient-reported outcome measures, and criterion validity using measures of strength. A floor or ceiling effect was indicated if more than 15% of patients achieved the lowest or highest possible score. RESULTS: The PROMIS UE had high internal consistency. Patients with early CMC OA had a lower score than healthy controls (average, 42 vs 54, respectively). We observed moderate to high correlations between the PROMIS UEv1.2, Australian and Canadian Osteoarthritis Hand Index, and Patient-Rated Wrist-Hand Evaluation and good criterion validity when compared to key pinch and grip strengths. The PROMIS UE did not correlate to radiographic disease severity. CONCLUSIONS: The PROMIS UE had a high correlation with Australian and Canadian Osteoarthritis Hand Index and a moderate correlation with Patient-Rated Wrist-Hand Evaluation. The PROMIS UE had high internal consistency and good criterion validity. CLINICAL RELEVANCE: The PROMIS UE is a valid assessment for disability in patients with early CMC OA and can serve as a clinical adjunct to an outcome assessment.

Medical Product Development Part 2: Patent and FDA Issues.

In part 2 of this review series on how to engage with the medical device industry as a surgeon, we summarize the patent application process. The federal government must approve any invention you might try to bring to market as safe-to-use for patients before any marketing can be initiated via the Food and Drug Administration submission process detailed herein.

Medical Product Development Part 1: Idea, Partnerships, and Commercialization.

The global orthopedic devices market is expected to reach nearly $72 billion by 2026, representing 12% of the projected global medical devices market. The vantage point of surgeons conveniently places them at the crossroads of surgery, therapy, and inpatient and outpatient dynamics, providing fertile ground for the invention of medical devices. This review article aims to provide an overview for how surgeons should take on launching a product in the medical device industry. In Part 1, we cover idea development, industry partnerships, and commercialization. Part 2 will cover the patent and United States Food and Drug Administration submission processes.

Kinematic Accuracy in Tracking Total Wrist Arthroplasty With Biplane Videoradiography Using a Computed Tomography-Generated Model.

Total wrist arthroplasty (TWA) for improving the functionality of severe wrist joint pathology has not had the same success, in parameters such as motion restoration and implant survival, as hip, knee, and shoulder arthroplasty. These other arthroplasties have been studied extensively, including the use of biplane videoradiography (BVR) that has allowed investigators to study the in vivo motion of the total joint replacement during dynamic activities. The wrist has not been a previous focus, and utilization of BVR for wrist arthroplasty presents unique challenges due to the design characteristics of TWAs. Accordingly, the aims of this study were (1) to develop a methodology for generating TWA component models for use in BVR and (2) to evaluate the accuracy of model-image registration in a single cadaveric model. A model of the carpal component was constructed from a computed tomography (CT) scan, and a model of the radial component was generated from a surface scanner. BVR was acquired for three anatomical tasks from a cadaver specimen. Optical motion capture (OMC) was used as the gold standard. BVR's bias in flexion/extension, radial/ulnar deviation, and pronosupination was less than 0.3 deg, 0.5 deg, and 0.6 deg. Translation bias was less than 0.2 mm with a standard deviation of less than 0.4 mm. This BVR technique achieved a kinematic accuracy comparable to the previous studies on other total joint replacements. BVR's application to the study of TWA function in patients could advance the understanding of TWA, and thus, the implant's success.

What Patient-related Factors are Associated with an Increased Risk of Surgery in Patients with Stenosing Tenosynovitis? A Prospective Study.

BACKGROUND: Numerous patient-related risk factors have been identified as contributors to patient progression to operative treatment of stenosing tenosynovitis (STS). Identifying patients most at risk of undergoing surgery after receiving a corticosteroid injection would enable health care providers to identify patients most likely to benefit from nonsurgical treatment. QUESTIONS/PURPOSES: (1) What proportion of prospectively enrolled patients with a new diagnosis of STS did not require further intervention after a first, second, or third injection when offered up to three corticosteroid injections? (2) Which identifiable risk factors present at the initial evaluation in patients with STS are associated with the patient opting for surgical release after a trial of one, two, or three corticosteroid injections? METHODS: One hundred ninety-six patients with a presumed diagnosis of STS were evaluated between March 2014 and June 2015, and 160 patients with 186 affected fingers were prospectively enrolled after a new diagnosis of STS was made during the study period. STS was diagnosed by assessing for tenderness at the A1 pulley, passive or active triggering, and the absence of other confounding diagnoses. Only the affected finger received a corticosteroid injection, and these patients were followed up during the study period. Patients were followed for 2 years, and 135 of the 160 patients (84%) completed the final followup. Patients with recurrent symptoms were treated with up to three corticosteroid injections before undergoing A1 pulley release, although patients could elect to undergo surgery at any time. Bivariate comparisons and a multivariate logistic regression analysis were used for independent fingers (one per participant) to identify independent variables associated with progression to surgery after injection. The time between treatments (between injection and subsequent injection or between injection and surgery) for those with recurrent symptoms was also calculated. Information collected from the last time the patient could be contacted was carried forward in the analysis for all 160 patients. RESULTS: No further treatment was sought after the first, second, and third injections by 81 of 160 (51%), 16 of 45 (37%), and three of 10 patients (30%), respectively; 100 of 160 patients (63%) did not pursue further intervention. After the first, second, and third injections, 36 of 160 patients (23%), 17 of 43 patients (40%), and seven of 10 of patients, respectively, did not respond to treatment. After controlling for 21 potentially confounding patient- and disease-related variables, we found that only two risk factors at the initial presentation were protective against eventual progression to surgery: osteoarthritis in the fingers (odds ratio [OR], 0.26 [95% CI, 0.085-0.786]; p = 0.017) and a longer duration of symptoms (OR, 0.58 [95% CI, 0.38-0.89]; p = 0.012). There was no association between progression to surgery and hand dominance, finger type (thumb or other), whether the patient had diabetes, or whether the affected finger was one of multiple affected fingers. Patients who presented again for intervention (injection or surgery) did so at a mean of 153 ± 94 days. CONCLUSIONS: Although patients should be counseled that their risk of progressing to surgery after an initial corticosteroid injection is lower than for subsequently administered injections for recurrent symptoms, nonoperative treatment should not be bypassed for patients with any of the studied risk factors. LEVEL OF EVIDENCE: Level II, therapeutic study.

Management of Diabetic Trigger Finger.

Diabetics have a much greater prevalence of trigger finger than nondiabetics and are more likely to have severe symptoms. Diabetic trigger finger may be more accurately described on a spectrum of diabetic hand pathology alongside carpal tunnel syndrome and cheiroarthropathy. Recent publications have called into question the current treatment algorithm for diabetic trigger finger. Although some evidence supports the use of corticosteroid injections, a recent cost analysis reported that immediate surgical release of the A1 pulley in the clinic is the most cost-effective management of diabetic trigger finger. In addition to traditional treatment with injection and open release, percutaneous release with or without simultaneous corticosteroid injection has shown promising results and may have a role in patient care. The appropriate treatment algorithm in terms of efficacy, safety, and cost remains controversial.

Suture Suspension Arthroplasty for the Treatment of Thumb Carpometacarpal Arthritis.

PURPOSE: Most studies have demonstrated little difference in the outcome of the various techniques proposed for the surgical treatment of thumb carpometacarpal (CMC) arthritis. However, the difficulty and time required to perform each technique vary widely. In addition, the introduction of recent implants has increased the cost of the overall procedure. We hypothesize that using a simple, yet stable, suture suspension technique without tendon interposition or ligament reconstruction yields similar results to conventional approaches with less operative time. METHODS: Three hundred twenty consecutive patients underwent thumb CMC arthroplasty by trapezial excision and metacarpal suspension using #2 high-strength orthopedic suture locked weave alone passed from the distal most abductor pollicis longus and flexor carpi radialis insertions without K-wire fixation or tendon transfer. Average duration of preoperative symptoms was 17.8 months. Patient radiographs were graded for arthritis severity and a visual analog scale (VAS) pain score (scale 0-10) obtained. Postoperative clinical and radiological follow-up averaged 5.4 years (minimum, 24 months). RESULTS: The average age at surgery was 57.3 years and there were 221 women (243 procedures) and 65 men (77 procedures). Average total operative time was 23.4 minutes. The dominant hand was involved in 52% of patients. All had prior treatment including orthoses and nonsteroidal anti-inflammatory drugs with 312 having had at least 1 steroid injection. Five patients had stage 1, 134 had stage 2, 164 had stage 3, and 17 had stage 4 disease on radiographs. Average trapezial space height on final follow-up radiographs was 0.8 cm. Two patients had complete trapezial space collapse and required a revision procedure. The average VAS score was 0.6 with pain eliminated in 269 thumbs, minimal in 49, and unchanged/worse in 2. All patients that were employed at the time of surgery returned to work at an average of 2.3 months (range, 3-16 weeks). CONCLUSIONS: Suture suspension thumb CMC arthroplasty provides comparable clinical results and several advantages over many current techniques that are described in the literature. The advantages include shortened operative time, inherent stability of the thumb metacarpal height, and no necessity for K-wire fixation, tendon transfers, or implants. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Silicone Metacarpophalangeal Arthroplasty for Osteoarthritis: Long-Term Results.

PURPOSE: To demonstrate that silicone metacarpophalangeal (MCP) arthroplasty provides excellent long-term outcomes with a low complication rate in osteoarthritis patients. METHODS: A consecutive cohort of 35 patients with osteoarthritis of 1 or more MCP joints undergoing anatomically neutral silicone MCP arthroplasty was followed over a 15-year period. Functional outcomes including strength and range of motion (ROM), as well as complications, were recorded. All patients were available for long-term assessment including radiographs and outcomes questionnaire. RESULTS: Average follow-up for the cohort of 35 patients (40 implants) was 8.3 years (range, 2-17 years). Average age was 58 years (range, 42-80 years) with 22 men and 13 women. In 31 patients, a single MCP joint was involved (middle finger, 20; index finger, 10; little finger, 1). The dominant hand was involved in 23 patients. Seven (of 14) patients had a concomitant RCL reconstruction of the index finger MCP joint; no other digit had a collateral ligament reconstruction. Average final visual analog scale pain score was 0.3 of 10. Average final active ROM arc was from 4° (range, 0°-20°) to 73° (range, 50°-90°) of flexion. One patient had a revision MCP arthroplasty for a 97% clinical survivorship. Radiographs demonstrated fractured implants in 5 of 40 (12.5%) implants, but none exhibited instability, pain, or ROM deterioration. Average Michigan Hand Outcomes Questionnaire score was 82 (of 100) at final follow-up. CONCLUSIONS: Silicone arthroplasty is effective in the treatment of primary MCP osteoarthritis. Implant survivorship is 97% (clinical) and 88% (radiographic) in long-term follow-up. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Thirty-Day Reoperation and/or Admission After Elective Hand Surgery in Adults: A 10-Year Review.

PURPOSE: Whereas acute complications following elective hand surgery have been assumed to be rare, the incidence of 30-day unplanned reoperation and/or admission for the most common elective procedures has not been well described. Our goal was to calculate the incidence and identify the risk factors associated with these complications in a busy academic practice. METHODS: Our institution's quality assurance database was examined retrospectively for unplanned reoperations and/or admissions within 30 days in adults undergoing elective procedures with 2 senior attending surgeons from February 2006 to January 2016. Each event was categorized by causative factor and charts were reviewed to establish risk factors and cultured organisms. Our billing database was examined for the concomitant procedural volume. RESULTS: In our cohort of 18,081 surgeries (57.6% carpal tunnel or trigger digit releases), 27 patients had an unplanned reoperation and/or admission within 30 days (0.15% total incidence; including carpal tunnel release, 0.10%; trigger digit release, 0.09%; major wrist surgery, 0.74%) including 17 infections (0.09%). These were unevenly distributed over time after surgery with 29.6% occurring within 7 days, 59.2% in 8 to 14 days, 11.1% in 15 to 21 days, and none between 22 and 30 days. CONCLUSIONS: Reoperations and/or unplanned admission within 30 days after elective hand surgery are infrequent (15 per 10,000 cases) and are most commonly related to infections (63.0%). More invasive surgeries are associated with a higher incidence than simpler procedures, and these complications are most likely to occur within 3 weeks after surgery. These data in elective patients do not cover certain clinically relevant outcomes, such as chronic pain or limited function, and may not be generalizable to all practices. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Cost-Effective Management of Stenosing Tenosynovitis.

PURPOSE: Stenosing tenosynovitis (STS) is a common condition treated by hand surgeons. Limited evidence exists to support the nonsurgical management of STS. The purpose of this study was to prospectively evaluate a cohort of patients with STS, and to determine the strategy for treating patients with this condition that is most cost effective in terms of dollars reimbursed by payers. METHODS: Prospective data were collected on patients diagnosed with STS between March 2014 and September 2014. All patients were initially treated with a corticosteroid injection. Patients with persistent symptoms were given the option of injection or surgery. A maximum of 3 injections were offered. All patients were evaluated every 6 months through office appointments or phone calls. A cost analysis was performed in our cohort using actual reimbursement rates for injections, initial and established patient visits, and facility and physician fees for surgery, using the reimbursement rates from the 6 payers covering this patient cohort. Cost savings were calculated based on offering 1, 2, and 3 injections. RESULTS: Eighty-eight digits in 82 patients were followed for an average of 21.9 months (range, 18.7-22.7 mo) after an initial corticosteroid injection. Thirty-five digits went on to surgical release, whereas 53 digits were treated nonsurgically. Had all patients initially undergone surgery, the cost would have totaled $169,088.98 ($1,921 per digit). Offering up to 3 injections yielded a potential savings of $72,730 ($826 per digit) or 43% of the total cost. For the 33 patients who underwent more than 1 injection, offering a second injection yielded potential savings of $15,956 ($484 per digit, 22.7%), and for the 7 patients presenting a third time, a third injection saved $1,986 ($283 per digit, 14.5%). CONCLUSIONS: Based on the data from our cohort, the efficient way to treat STS in terms of health care dollars spent is to offer up to 3 injections before surgical release. The first injection had the highest component of cost savings, at $826 per digit. TYPE OF STUDY/LEVEL OF EVIDENCE: Economic/Decision Analysis III.

High Survivorship and Few Complications With Cementless Total Wrist Arthroplasty at a Mean Followup of 9 Years.

BACKGROUND: Total wrist arthroplasty (TWA) has been described as traditionally being performed with fixation in the radius and carpus with cement. The TWA implant used in our series has been associated with promising results in studies with up to 6 years followup; however, studies evaluating survivorship, pain, and function with this implant are limited. QUESTION/PURPOSE: (1) To report ROM and pain scores after wrist reconstruction with cementless fourth-generation TWA at a mean followup of 9 years (range, 4.8-14.7 years). (2) To report complications of a cementless fourth-generation TWA and the cumulative probability of not undergoing a revision at a mean followup of 9 years. METHODS: This is a retrospective case series of 69 patients who were treated for pancarpal wrist arthritis between 2002 and 2014. Of those, 31 had inflammatory arthritis (rheumatoid arthritis [n = 29], juvenile rheumatoid arthritis [n = 1], and psoriatic arthritis [n = 1]); all of these patients received TWA with the cementless implant studied in this investigation. Another 38 patients had osteoarthritis or posttraumatic arthritis; in this subgroup, 28 patients were 65 years or younger, and all underwent wrist fusion (none were offered TWA). Ten patients with osteoarthritis were older than 65 years and all were offered TWA; of those, eight underwent TWA, and two declined the procedure and instead preferred and underwent total wrist arthrodesis. The mean age of the 39 patients who had TWA was 56 ± 8.9 years (range, 31-78 years) at the time of surgery; 36 were women and three were men. The patients who underwent TWA were seen at a minimum of 4 years (mean, 9 years; range, 4-15 years), and all had been examined in 2016 as part of this study except for one patient who died 9 years after surgery. The dominant wrist was involved in 60% (25) of the patients. All patients were immobilized for 4 weeks postoperatively and then underwent hand therapy for 4 to 6 weeks. Pain and ROM were gathered before surgery as part of clinical care, and were measured again at latest followup; at latest followup, radiographs were analyzed (by the senior author) for evidence of loosening, defined as any implant migration compared with any previous radiograph with evidence of periimplant osteolysis and bone resorption. Subjective pain score was assessed by a verbal pain scale (0-10) and ROM was measured with a goniometer. Complications were determined by chart review and final examination. Kaplan Meier survival analysis was performed to estimate the cumulative probability of not undergoing a revision. RESULTS: The mean preoperative active ROM was 34o ± 18° flexion and 36° ± 18° extension. Postoperatively, the mean active ROM was 37° ± 14° flexion and 29° ± 13° extension. The mean difference between the preoperative pain score (8.6 ± 1.2) and postoperative pain score (0.4 ± 0.8) was 8.1 ± 1.9 (p < 0.001). Implant loosening occurred in three (7.7%) patients. No other complications occurred in this series. Kaplan-Meier survivorship analysis estimated the cumulative probability of remaining free from revision as 78% (95% CI, 62%-91%) at 15 years. CONCLUSION: Cementless fourth-generation TWA improves pain while generally preserving the preoperative arc of motion. The cumulative probability of remaining free from revision at 14.7 years after the index procedure is 77.7% (95% CI, 62.0%-91.4%). Future studies should compare alternative approaches for patients with endstage wrist arthritis; such evaluations-which might compare TWA implants, or TWAs with arthrodesis-will almost certainly need to be multicenter, as the problem is relatively uncommon. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Negotiation: How to Be Effective.

The art of successful negotiation is not as random or difficult as it might seem at first glance. Most negotiations end up with both sides receiving something of value as well as giving up something valuable in return. It has been said that the best negotiated outcomes occur when both parties walk away a bit disappointed or just a little bit happy. The goal of this short primer is to give some hints as to how to get a slightly better deal than the other party most of the time. There are several points to remember to be able to achieve such an outcome frequently.

Total Wrist Arthroplasty.

Total wrist arthroplasty using current design implants has evolved into a fairly predictable procedure for rheumatoid, osteoarthritic, and posttraumatic patients. Although complications can occur, the incidence of these has dropped over the past decade with implant design modifications. The article summarizes the current use of total wrist arthroplasty and touches on issues of revision surgery, secondary fusion, complications, wrist fusion takedown, and radiolucency around implants. Technical tips are also provided for both primary and revision surgery.

Crush Injuries of the Hand.

Crush injuries of the hand are a rare but devastating phenomenon, with historically poor outcomes. A compressive force, usually caused by a high-energy mechanism such as a motor vehicle or industrial accident, crushes and transiently increases the pressures within the hand. This force acts on the incompressible blood in the vasculature and leads to a dramatic rise in tissue pressures and damage to multiple tissue types, including bones, blood vessels, nerves, and soft tissues. A wide zone of injury results from a delayed inflammatory reaction involving the zone bordering the crushed cells, which may initially belie the severity of the injury. As such, these injuries go on to produce tremendous inflammation and swelling, potentially followed by compartment syndrome or other vascular damage, infection, neurological injury, and tissue necrosis. Crush injuries with minimal skin disruptions can be particularly challenging to accurately diagnose and manage. This paper provides a review of the initial evaluation of hand crush injuries as well as short- and long-term management strategies.

Correlation of clinical disease severity to radiographic thumb osteoarthritis index.

PURPOSE: To determine if a slight modification of the 1987 Eaton-Glickel staging and interpreting 4 standardized radiographs for trapeziometacarpal (TMC) osteoarthritis (OA) improved analysis, to determine if a quantifiable index measurement from a single Robert (pronated anteroposterior) view enhanced reproducibility, and to examine whether improved radiographic staging correlated to clinically relevant disease and thus support validity. METHODS: We analyzed 4 thumb radiographs (posteroanterior, lateral, Robert, and stress views) in 60 consecutive subjects representing an adult population spectrum of asymptomatic to advanced disease. Two experienced hand surgeons (A.L.L. and A.P.C.W.), 1 chief resident (A.J.B.), and 1 medical student (J.M.M.) performed the analysis on each subject's radiographs. We analyzed all 4 radiographs for Eaton and modified Eaton staging and then later analyzed only the Robert view for the thumb osteoarthritis (ThOA) index measurement. The radiographs were randomized and reread a week later for each classification at separate times. Surgically excised trapeziums from 20/60 subjects were inspected for first metacarpal surface disease and correlated to the 3 classifications. RESULTS: All 3 staging classifications demonstrated high reproducibility, with the intraclass correlation coefficient averaging 0.73 for the Eaton, 0.83 for the modified Eaton, and 0.95 for the ThOA index. Articular wear and metacarpal surface eburnation correlated highest to the ThOA index, with advanced disease 1.55 or greater correlating to Eaton III/IV and modified Eaton stage 3/4 in a linear relationship. CONCLUSIONS: The ThOA index based on a Robert view provided a measurable alternative to Eaton staging and correlated to severity of surgically relevant thumb TMC OA. CLINICAL RELEVANCE: A simple reproducible radiographic measurement may enhance TMC OA classification and provide a reliable means to predict clinical disease. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

In Vivo kinematics of the trapeziometacarpal joint during thumb extension-flexion and abduction-adduction.

PURPOSE: The primary aim of this study was to determine whether the in vivo kinematics of the trapeziometacarpal (TMC) joint differ as a function of age and sex during thumb extension-flexion (Ex-Fl) and abduction-adduction (Ab-Ad) motions. METHODS: The hands and wrists of 44 subjects (10 men and 11 women with ages 18-35 y and 10 men and 13 women with ages 40-75 y) with no symptoms or signs of TMC joint pathology were imaged with computed tomography during thumb extension, flexion, abduction, and adduction. The kinematics of the TMC joint were computed and compared across direction, age, and sex. RESULTS: We found no significant effects of age or sex, after normalizing for size, in any of the kinematic parameters. The Ex-Fl and Ab-Ad rotation axes did not intersect, and both were oriented obliquely to the saddle-shaped anatomy of the TMC articulation. The Ex-Fl axis was located in the trapezium and the Ab-Ad axis was located in the metacarpal. Metacarpal translation and internal rotation occurred primarily during Ex-Fl. CONCLUSIONS: Our findings indicate that normal TMC joint kinematics are similar in males and females, regardless of age, and that the primary rotation axes are nonorthogonal and nonintersecting. In contrast to previous studies, we found Ex-Fl and Ab-Ad to be coupled with internal-external rotation and translation. Specifically, internal rotation and ulnar translation were coupled with flexion, indicating a potential stabilizing screw-home mechanism. CLINICAL RELEVANCE: The treatment of TMC pathology and arthroplasty design require a detailed and accurate understanding of TMC function. This study confirms the complexity of TMC kinematics and describes metacarpal translation coupled with internal rotation during Ex-Fl, which may explain some of the limitations of current treatment strategies and should help improve implant designs.

The 2014 ABJS Nicolas Andry Award: The puzzle of the thumb: mobility, stability, and demands in opposition.

BACKGROUND: The paradoxical demands of stability and mobility reflect the purpose and function of the human thumb. Its functional importance is underscored when a thumb is congenitally absent, injured, or afflicted with degenerative arthritis. Prevailing literature and teaching implicate the unique shape of the thumb carpometacarpal (CMC) joint, as well as its ligament support, applied forces, and repetitive motion, as culprits causing osteoarthritis (OA). Sex, ethnicity, and occupation may predispose individuals to OA. QUESTIONS/PURPOSES: What evidence links ligament structure, forces, and motion to progressive CMC disease? Specifically: (1) Do unique attributes of the bony and ligamentous anatomy contribute to OA? (2) Can discrete joint load patterns be established that contribute to OA? And (3) can thumb motion that characterizes OA be measured at the fine and gross level? METHODS: We addressed the morphology, load, and movement of the human thumb, emphasizing the CMC joint in normal and arthritic states. We present comparative anatomy, gross dissections, microscopic analysis, multimodal imaging, and live-subject kinematic studies to support or challenge the current understanding of the thumb CMC joint and its predisposition to disease. RESULTS: The current evidence suggests structural differences and loading characteristics predispose the thumb CMC to joint degeneration, especially related to volar or central wear. The patterns of degeneration, however, are not consistently identified, suggesting influences beyond inherent anatomy, repetitive load, and abnormal motion. CONCLUSIONS: Additional studies to define patterns of normal use and wear will provide data to better characterize CMC OA and opportunities for tailored treatment, including prevention, delay of progression, and joint arthroplasty.