Carpal kinematics after proximal row carpectomy

Proximal row carpectomy or scaphoid excision and four-corner arthrodesis for treatment of scapholunate advanced collapse arthritis

Degenerative wrist conditions, such as scapholunate advanced collapse and scaphoid nonunion advanced collapse, often require salvage procedures to reduce pain and improve function. For early stages of disease, both proximal row carpectomy and scaphoid excision four-corner arthrodesis are viable motion-preserving options. There remains controversy on which technique is superior. Selection is a nuanced decision that requires consideration of patient characteristics and stage of disease. The traditional notion that proximal row carpectomy should be reserved for older individuals with low demands has been challenged; long-term studies in younger populations demonstrate similar patient-reported outcomes, pain relief and survivorship without conversion to total wrist arthrodesis between proximal row carpectomy and four-corner arthrodesis. The existing evidence suggests proximal row carpectomy has advantages of greater range of motion, fewer complications and lower costs. Advancements such as arthroscopic techniques for both procedures show potential, although mastery involves a steep learning curve.

Scapholunate Advanced Collapse (SLAC) and Scaphoid Nonunion Advanced Collapse (SNAC): A Review of Treatment Options for Stage II

Scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) represent clinical entities identified by a pattern of predictable degenerative changes. They are the most common causes of wrist arthritis. Both entities can remain asymptomatic for many years and may go undiagnosed. Diagnosis is usually confirmed through clinical examination, which reveals progressive wrist pain and instability. Radiographically, degenerative changes in the radiocarpal and midcarpal joints are present, as well as nonunion of the scaphoid fracture in SNAC. The management differs according to the stage. Particularly in this review article, we reviewed the treatment options for stage II SLAC and SNAC wrist. In addition to the well-described surgical techniques such as proximal row carpectomy and four-corner fusion, alternatives such as capitolunate arthrodesis, three-corner fusion, and soft tissue procedures like capsulodesis and tenodesis are available. Proximal row carpectomy and partial arthrodeses yield comparable results. Soft tissue procedures are viable alternatives and are preferred in younger patients to avoid early salvage operations.

Dorsal lunate dislocation and en bloc proximal row carpectomy: a case report

An unhelmeted 59-year-old male involved in a motorcycle accident presented with a right dorsal lunate dislocation in the context of a polytrauma evaluation. Soft-tissue attachments were minimal across the carpus, which allowed for an en bloc proximal row carpectomy. Two-year follow-up yielded a satisfactory outcome given the high energy injury mechanism. Proximal row carpectomy is a useful tool which preserves wrist range of motion in the acute trauma setting and is durable, as demonstrated by our patient's postoperative mobilization using a wheelchair.

Proximal Row Carpectomy Does Not Alter Contact Pressures of the Lunate Fossa: A Cadaveric Study

BACKGROUND

Previous studies have suggested that proximal row carpectomy (PRC) results in increased contact pressures and decreased contact areas in the radiocarpal joint. Such experiments, however, used older technologies that may be associated with considerable measurement errors. The purpose of this study was to determine whether there was a significant difference in contact pressure and contact area before and after PRC using Tekscan, a newer pressure sensing technology.

METHODS

Ten nonpaired cadaveric specimens were dissected proximal to the carpal row and potted. An ultra-thin Tekscan sensor was secured in the lunate fossa of the radius. The wrists were loaded with 200 N of force for 60 seconds to simulate clenched-fist grip; contact pressure and area was assessed before and after PRC.

RESULTS

Performing a PRC did not significantly increase mean contact pressure at the lunate fossa compared to the native state (mean increase of 17.4 ± 43.2 N/cm2, P = .184). Similarly, the PRC did not significantly alter peak contact pressures at the lunate fossa (intact: 617.2 ± 233.46 N/cm2, median = 637.5 N/cm2; PRC: 707.8 ± 156.6 N/cm2, median = 728.5 N/cm2; P = .169). In addition, the PRC (0.46 ± 0.15 cm2, median = 0.48 cm2) and intact states (0.49 ± 0.25 cm2, median = 0.44 cm2) demonstrated similar contact areas (P = .681).

CONCLUSIONS

In contrast to prior studies that demonstrated significant increases in contact pressure and decreases in contact area after PRC, our findings propose that performing a PRC does not significantly alter the contact pressures or area of the lunate fossa of the radiocarpal joint.

Carpal Kinematics in Madelung Deformity

PURPOSE

Various skeletal and soft tissue abnormalities have been identified in Madelung deformity and have been hypothesized to play a causal role in its progressive symptomatology; however, our pathological understanding of these changes remains limited. In this study, we biomechanically assessed the Madelung deformity wrist, using 4-dimensional computed tomography imaging.

METHODS

Nine Madelung deformity wrists (5 patients; age, 24 ± 5 y) and 18 healthy wrists (9 volunteers; age, 28 ± 3 y) underwent 4-dimensional imaging during flexion-extension motion and radioulnar deviation. Carpal kinematics and radiocarpal joint parameters were quantified and compared.

RESULTS

In Madelung deformity wrists, significantly decreased rotation was seen in the lunate (-4.6°) and the triquetrum (-4.8°) during flexion-extension motion. During radioulnar deviation, significant decreases were visible in lunate bone translation (-0.7 mm), triquetrum bone translation (-0.6 mm), and triquetrum bone rotation (-1.9°). Patients had significantly decreased articulating surface areas of the scaphoid (1.4 ± 0.2 cm² versus 1.6 ± 0.2 cm²) and lunate (1.2 ± 0.4 cm² versus 1.5 ± 0.3 cm²) fossa, and significantly increased radioscaphoid (1.3 ± 0.1 mm versus 1.2 ± 0.1 mm) and radiolunate (1.6 ± 0.2 mm versus 1.3 ± 0.3 mm) joint space thicknesses.

CONCLUSIONS

There is a decreased mobility of the lunate and triquetrum bones in Madelung deformity.

CLINICAL RELEVANCE

Four-dimensional imaging could be used in future studies that investigate the effect of surgical ligament release on carpal kinematics and subsequent wrist mobility.

The effect of four-corner fusion and proximal row carpectomy on uniplanar and multiplanar wrist motion: A biomechanical study

Purpose

To compare changes in wrist kinematics after scaphoidectomy and four-corner fusion (4CF), and proximal row carpectomy (PRC).

Methods

Six cadaveric specimens underwent flexion-extension, radial-ulnar deviation and circumduction in an active motion wrist simulator. Native state, "anatomic 4CF", "radial 4CF", and PRC were compared.

Results

Radial 4CF reduced wrist extension, while PRC reduced radial deviation. Fusion groups had similar motion profiles. 44%, 41%, and 32% of native circumduction was maintained in PRC, anatomic, and radial 4CF.

Conclusions

Both fusion positions resulted in comparable motion outcomes. Anatomic 4CF was restricted in wrist extension compared to PRC but provided favourable radial deviation.

Functional Outcomes After Salvage Procedures for Wrist Trauma and Arthritis (Four-Corner Fusion, Proximal Row Carpectomy, Total Wrist Arthroplasty, Total Wrist Fusion, Wrist Denervation): A Review of Literature

Background:

Several salvage procedures for the arthritically destroyed wrist exist. Each of these has advantages as well as disadvantages.

Aims:

The aim of this article is to give practical insights for the clinician on: (1) biomechanical and clinical fundamentals of normal and impaired wrist motion; (2) difficulties in assessment of postoperative outcome between measured motion by the surgeon and self-reported outcome by the patient; (3) indications for each procedure; and (4) differences in functional outcome between partial and complete motion-preserving as well as complete motion-restricting salvage procedures.

Methods:

In trend, Proximal Row Carpectomy (PRC) is slightly superior over four-corner fusion (4CF) in terms of functional outcome, but the methodology-related postoperative motion is decreased for both procedures. Furthermore, PRC is easier to perform, needs lower costs, and has fewer complications than 4CF. Total Wrist Arthroplasty (TWA) has the advantage compared to PRC and 4CF that the preoperative motion values are preserved, but it is limited by decreased load-bearing capacity for the wrist. Total Wrist Fusion (TWF) is associated with a higher load-bearing capacity for the wrist than TWA, but it is limited for carrying out essential activities of daily living. Both PRC and 4CF can be combined primarily by wrist denervation. Wrist denervation alone does not impair the movement of the wrist.

Results and Conclusion:

Salvage procedures for the arthritically destroyed wrist should be detected regarding patients age- and gender-related claims in work and leisure. Not all of them can be successfully re-employed in their original occupations associated with high load-bearing conditions.

Evaluation of the performance of three tenodesis techniques for the treatment of scapholunate instability: flexion-extension and radial-ulnar deviation

Chronic scapholunate ligament (SL) injuries are difficult to treat and can lead to wrist dysfunction. Whilst several tendon reconstruction techniques have been employed in the management of SL instability, SL gap reappearance after surgery has been reported. Using a finite element model and cadaveric study data, we investigated the performance of the Corella, scapholunate axis (SLAM) and modified Brunelli tenodesis (MBT) techniques. Scapholunate dorsal and volar gap and angle were obtained following virtual surgery undertaken using each of the three reconstruction methods with the wrist positioned in flexion, extension, ulnar deviation and radial deviation, in addition to the ulnar-deviated clenched fist and neutral positions. From the study, it was found that, following simulated scapholunate interosseous ligament rupture, the Corella technique was better able to restore the SL gap and angle close to the intact ligament for all wrist positions investigated, followed by SLAM and MBT. The results suggest that for the tendon reconstruction techniques, the use of multiple junction points between scaphoid and lunate may be of benefit.

Graphical abstract

Four-dimensional rotational radiographic scanning of the wrist in patients after proximal row carpectomy

We measured cartilage thickness, contact surface area, volume of the capitate and shape of the capitate during motion in the operated and unaffected wrists of 11 patients with a mean follow-up of 7.3 years after proximal row carpectomy. Radiocapitate cartilage thickness in the operated wrists did not differ significantly from radiolunate cartilage thickness in the unaffected wrists. The radiolunate surface area was significantly less than the radiocapitate surface area. The volume of the capitate was significantly increased in the operated wrists. The shape of the capitate changed significantly in two of three orthogonal directions. The combination of remodelling of the capitate, increase in its surface area and intact cartilage thickness could help to explain the clinical success of proximal row carpectomy.

Proximal Row Carpectomy and 4-Corner Arthrodesis in Patients Younger Than Age 45 Years

PURPOSE

To examine the long-term outcome of patients aged less than 45 years who underwent either proximal row carpectomy (PRC) or 4-corner arthrodesis (4CA) for wrist arthritis.

METHODS

We reviewed a retrospective cohort of 89 patients aged less than 45 years who underwent either 4CA (n = 51) or PRC (n = 38) for wrist arthritis. Mean follow-up was 11 years in the 4CA group and 18 years in the PRC group.

RESULTS

Overall, there were no differences between groups in the need for revision surgery. Complications included 6 nonunions in the 4CA group (12%), 1 infection in each group, and 11 patients who experienced radiocarpal impingement (8 4CA and 3 PRC). There was no difference in the number of patients reporting moderate or severe pain between the PRC and 4CA groups. Mean flexion-extension arc was 54° after 4CA, compared with 73° after PRC. Patients who underwent 4CA had slightly improved grip strength (65% of the opposite side) compared with those who had PRC (54%). Mean postoperative Disabilities of the Arm, Shoulder, and Hand questionnaire scores were 32 versus 19 (PRC vs 4CA) and patient-rated wrist evaluation scores were 27 versus 28 (PRC vs 4CA). Comparing radiographic arthritis, the 10-year outcome, free of moderate/severe arthritis for the PRC and 4CA groups, was 70% and 71%, respectively.

CONCLUSIONS

Both PRC and 4CA represent a good surgical option for young patients with wrist arthritis, with similar complication rates, postoperative pain levels, wrist function, and long-term outcomes free of arthrodesis. Proximal row carpectomy has improved motion and fewer complications.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Connecting the wrist to the hand: A simulation study exploring changes in thumb-tip endpoint force following wrist surgery

The wrist is essential for hand function. Yet, due to the complexity of the wrist and hand, studies often examine their biomechanical features in isolation. This approach is insufficient for understanding links between orthopaedic surgery at the wrist and concomitant functional impairments at the hand. We hypothesize that clinical reports of reduced force production by the hand following wrist surgeries can be explained by the surgically-induced, biomechanical changes to the system, even when those changes are isolated to the wrist. This study develops dynamic simulations of lateral pinch force following two common surgeries for wrist osteoarthritis: scaphoid-excision four-corner fusion (SE4CF) and proximal row carpectomy (PRC). Simulations of lateral pinch force production in the nonimpaired, SE4CF, and PRC conditions were developed by adapting published models of the nonimpaired wrist and thumb. Our simulations and biomechanical analyses demonstrate how the increased torque-generating requirements at the wrist imposed by the orthopaedic surgeries influence force production to such an extent that changes in motor control strategy are required to generate well-directed thumb-tip end-point forces. The novel implications of our work include identifying the need for surgeries that optimize the configuration of wrist axes of rotation, rehabilitation strategies that improve post-operative wrist strength, and scientific evaluation of motor control strategies following surgery. Our simulations of SE4CF and PRC replicate surgically-imposed decreases in pinch strength, and also identify the wrist's torque-generating capacity and the adaptability of muscle coordination patterns as key research areas to improve post-operative hand function.

Intercarpal fusions: indications, treatment options and techniques

Partial wrist fusion is a useful technique for the treatment of such specific carpal disorders as arthritis, Kienböck's disease, midcarpal instability, scaphoid nonunion, etc.Many techniques have been described by removing arthritic joint surfaces and transfering load, using, for bone fixation, K-wires, screws, staples, and more recently dedicated plates.The goal of this procedure is to maximise wrist motion and strength while minimizing or eliminating pain.The purpose of this article is to discuss the most commonly used combination of intercarpal arthrodeses, to clarify the indications for each fusion, to describe the appropriate surgical technique for each fusion, and to provide an overview of results and current concepts. Cite this article: Houvet, P. Intercarpal fusions: indications, treatment options and techniques. EFORT Open Rev 2016;1:45-51. DOI: 10.1302/2058-5241.1.000019.

Comparison of activities of daily living after proximal row carpectomy or wrist four-corner fusion

Proximal row carpectomy and four-corner fusion are commonly used in the patients with scaphoid nonunion advanced collapse or scapholunate advanced collapse. We compared activities of daily living of the 24 patients after proximal row carpectomy with 24 patients with four-corner fusion procedures using the modified Sollerman hand function test and Michigan Hand Questionnaire. Most tasks were performed significantly quicker by the patients after proximal row carpectomy. The patients after proximal row carpectomy reported better function during activities of daily living.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Proximal row carpectomy on manual workers: 17 patients followed for an average of 6 years

Proximal row carpectomy (PRC) is indicated for the treatment of SNAC or SLAC wrist with preservation of the midcarpal joint. Our hypothesis was that PRC is not appropriate for treating advanced wrist osteoarthritis in patients who carry out heavy manual work. Twenty-three PRCs were performed on 21 patients, 5 women and 16 men with an average age of 54 years (33-77). All patients performed manual work; 11 of them performed heavy manual work. Etiologies were: SLAC wrist in 14 cases (2 stage III, 11 stage II, and 1 stage I) and SNAC wrist in 9 cases (6 stage IIIB and 3 stage IIB). At an average 75 months' follow-up (24-153), five patients were lost to follow-up. Radiocarpal arthrodesis was performed in one patient 10 years after the PRC. In the 17 remaining patients (18 wrists), pain (VAS) averaged 2.2, with residual pain of 5. Flexion-extension range was similar to preoperative levels (67% of contralateral wrist). Wrist strength was decreased by 34% compared to preoperative. The QuickDASH score averaged 26 points and the PRWE 20 points. Radiocapitate distance decreased by 0.3mm on average with joint line narrowing in 6 patients. The carpal translation index was 0.33mm, which was unchanged relative to preoperative values. Three patients had work-related limitations that required retraining and one patient had to be reassigned. PRC preserved the preoperative range of motion and reduced pain levels. However, significant loss of strength was observed, resulting in 23% of manual workers needing retraining or reassignment.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Decoupling the Wrist: A Cadaveric Experiment Examining Wrist Kinematics Following Midcarpal Fusion and Scaphoid Excision

At the wrist, kinematic coupling (the relationship between flexion-extension and radial-ulnar deviation) facilitates function. Although the midcarpal joint is critical for kinematic coupling, many surgeries, such as 4-corner fusion (4CF) and scaphoidexcision 4-corner fusion (SE4CF), modify the midcarpal joint. This study examines how 4CF and SE4CF influence kinematic coupling by quantifying wrist axes of rotation. Wrist axes of rotation were quantified in 8 cadaveric specimens using an optimization algorithm, which fit a 2-revolute joint model to experimental data. In each specimen, data measuring the motion of the third metacarpal relative to the radius was collected for 3 conditions (nonimpaired, 4CF, SE4CF). The calculated axes of rotation were compared using spherical statistics. The angle between the axes of rotation was used to assess coupling, as the nonimpaired wrist has skew axes (ie, angle between axes approximately 60°). Following 4CF and SE4CF, the axes are closer to orthogonal than those of the nonimpaired wrist. The mean angle (±95% confidence interval) between the axes was 92.6° ± 25.2° and 99.8° ± 22.0° for 4CF and SE4CF, respectively. The axes of rotation defined in this study can be used to define joint models, which will facilitate more accurate computational and experimental studies of these procedures.

Distal Radius Hemiarthroplasty

INTRODUCTION

Due to a higher risk for implant loosening, particularly of the distal component, patients with physically demanding lifestyles are infrequently considered for total wrist arthroplasty (TWA). A distal radius hemiarthroplasty may obviate the need for the strict restrictions recommended for patients treated by TWA, thus providing another surgical option for active patients with severe wrist arthritis, especially those with articular degeneration of the lunate facet of the radius, capitate head, or combination of both, who are not typically candidates for traditional motion-preserving procedures.

MATERIALS AND METHODS

Eight fresh-frozen cadaver limbs (age range, 43-82 years) with no history of rheumatoid arthritis or upper extremity trauma were used. Radiodense markers were inserted in the radius and hand. Posteroanterior (PA) fluoroscopic images with the wrist in neutral, radial deviation, and ulnar deviation, and lateral images with the wrist in neutral, flexion, and extension were obtained for each specimen before implantation, after distal radius hemiarthroplasty, and after combined hemiarthroplasty and PRC.

RESULTS

On the PA images, the capitate remained within 1.42 and 2.21 mm of its native radial-ulnar position following hemiarthroplasty and hemiarthroplasty with PRC, respectively. Lateral images showed the capitate remained within 1.06 mm of its native dorsal-volar position following hemiarthroplasty and within 4.69 mm following hemiarthroplasty with PRC. Following hemiarthroplasty, capitate alignment changed 2.33 and 2.59 mm compared with its native longitudinal alignment on PA and lateral films, respectively. These changes did not reach statistical significance. As expected, significant shortening in longitudinal alignment was seen on both PA and lateral films for hemiarthroplasty with PRC.

CONCLUSION

A distal radius implant hemiarthroplasty with or without a PRC provides good static alignment of the wrist in a cadaver model and thus supports the concept as potential treatment alternatives for advanced wrist arthritis; however, combined hemiarthroplasty with a PRC has more clinical relevance because it avoids the risk of proximal carpal row instability and eliminates the commonly arthritic radioscaphoid joint.

Surgical Simulations Based on Limited Quantitative Data: Understanding How Musculoskeletal Models Can Be Used to Predict Moment Arms and Guide Experimental Design

The utility of biomechanical models and simulations to examine clinical problems is currently limited by the need for extensive amounts of experimental data describing how a given procedure or disease affects the musculoskeletal system. Methods capable of predicting how individual biomechanical parameters are altered by surgery are necessary for the efficient development of surgical simulations. In this study, we evaluate to what extent models based on limited amounts of quantitative data can be used to predict how surgery influences muscle moment arms, a critical parameter that defines how muscle force is transformed into joint torque. We specifically examine proximal row carpectomy and scaphoid-excision four-corner fusion, two common surgeries to treat wrist osteoarthritis. Using models of these surgeries, which are based on limited data and many assumptions, we perform simulations to formulate a hypothesis regarding how these wrist surgeries influence muscle moment arms. Importantly, the hypothesis is based on analysis of only the primary wrist muscles. We then test the simulation-based hypothesis using a cadaveric experiment that measures moment arms of both the primary wrist and extrinsic thumb muscles. The measured moment arms of the primary wrist muscles are used to verify the hypothesis, while those of the extrinsic thumb muscles are used as cross-validation to test whether the hypothesis is generalizable. The moment arms estimated by the models and measured in the cadaveric experiment both indicate that a critical difference between the surgeries is how they alter radial-ulnar deviation versus flexion-extension moment arms at the wrist. Thus, our results demonstrate that models based on limited quantitative data can provide novel insights. This work also highlights that synergistically utilizing simulation and experimental methods can aid the design of experiments and make it possible to test the predictive limits of current computer simulation techniques.

Factors associated with improved outcomes following proximal row carpectomy: a long-term outcome study of 144 patients

We conducted a review of 144 consecutive patients who underwent proximal row carpectomy from 1967 to 2010 for the diagnosis of wrist arthritis. At a mean follow-up of 13.4 years, patients experienced good pain relief with preservation (but not improvement) of wrist motion. A total of 17 patients (12%) required revision surgery at an average of 44.6 months. Improved pain, function, and survival outcomes were seen in those who underwent proximal row carpectomy after the age of 40, had a preoperative diagnosis of Kienbock's disease, who underwent a concomitant neurectomy procedure, patients who were non-labourers, and patients who underwent surgery after 1990. Although 45% of patients developed moderate to severe radiocapitate arthrosis postoperatively, these findings did not correlate with clinical outcomes or risk of revision surgery. Patients with type II lunate and type II and III capitate shapes had higher rates of postoperative radiocapitate arthrosis.

LEVEL OF EVIDENCE

III, Prognostic.

A Cadaver Investigation of Screw Purchase With 2 Retrograde Techniques for Capitolunate Arthrodesis

PURPOSE

To examine the hypothesis that the amount of bone purchase within the lunate is greater when using a technique for intermetacarpal retrograde screw placement across the capitolunate joint than when using a dorsal capitate technique.

METHODS

Seven fresh cadaver limbs were dissected. We exposed the carpus and scaphoidectomy and performed selective capitolunate decortication. We compared the technique of dorsal capitate placement of headless compression screws with intermetacarpal placement by measuring the depth of purchase in the lunate.

RESULTS

Drill hole depths in the lunate were greater using the intermetacarpal technique versus the dorsal capitate technique; the average depth was 9.0 and 6.4 mm, respectively. The calculated number of threads was also greater with the intermetacarpal technique than with the dorsal capitate technique (15 vs 9 threads, respectively).

CONCLUSIONS

The intermetacarpal technique for retrograde headless compression screw placement in a capitolunate arthrodesis provided a greater depth of purchase in the lunate portion of the construct. It also afforded more ease of placement than previously described antegrade techniques without the risk of hardware migration into the radiocarpal joint.

CLINICAL RELEVANCE

The knowledge gained from this study may help guide surgeons to choose a technique for retrograde placement of headless compression screws in capitolunate arthrodesis to gain better purchase within the lunate.

Four-Corner Arthrodesis Versus Proximal Row Carpectomy: A Retrospective Study With a Mean Follow-Up of 17 Years

PURPOSE

To compare the long-term outcomes of proximal row carpectomy (PRC) and 4-corner arthrodesis (FCA) in a consecutive series of patients surgically treated between 1989 and 1998 in a single teaching hospital.

METHODS

We included 12 patients (14 wrists) in the PRC group and 8 patients (8 wrists) in the FCA group. Mean follow-up time was 17 years. We compared functional outcome measures (range of motion and grip strength) and patient-reported outcome measures (visual analog score for pain, Mayo Wrist Score, and Michigan Hand Questionnaire). Radiographic evaluation of joint degeneration using the Culp and Jebson scoring system and postoperative complications were assessed for both groups.

RESULTS

Active range of motion was slightly better after PRC. There were no differences in grip strength and patient-reported outcomes between groups. Severity of degenerative changes did not differ between groups and was not correlated with pain scores. The FCA group showed more postoperative complications.

CONCLUSIONS

Considering the objective and patient-reported outcomes of this study, both types of surgery perform well in the long run. Proximal row carpectomy seems to result in slightly better movement of the wrist with fewer surgical complications and no need for hardware removal. Moreover, postoperative immobilization time was much shorter.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

Radiocapitate congruency as a predictive factor for the results of proximal row carpectomy

PURPOSE

To evaluate whether the congruency between the joint surfaces of the lunate fossa of the distal radius and the proximal capitate might be a prognostic factor for functional, clinical, or radiographic results after proximal row carpectomy (PRC).

METHODS

After reconstructing the computed tomographic arthrogram of patients with PRC, we evaluated the shape of the proximal capitate by measuring the radius of curvature of the tip of the capitate. The congruency of the future radiocapitate joint was then evaluated by the radiocapitate index in the frontal and sagittal planes. This was calculated by dividing the radius of curvature of the tip of the capitate by the mean radius of curvature of the lunate fossa. We determined the relationship between these morphological results and the functional (Disabilities of the Arm, Shoulder, and Hand [DASH] score, Mayo Wrist score, and pain relief), clinical (mobility and strength) and x-ray results (radiocapitate arthrosis).

RESULTS

A total of 27 patients were reviewed at a mean follow-up of 59 months. The shape of the proximal capitate did not affect outcomes. In the frontal plane, a better radiocapitate congruency was significantly associated with an increase in wrist flexion and better functional results for the DASH. There was a non-significant relationship between congruency and improvement of Mayo Wrist score and pain relief. In the sagittal plane, the DASH score tended to improve when congruency was better.

CONCLUSIONS

The shape of the capitate was not a prognostic factor for functional outcome after PRC. The radiocapitate index seems more relevant in predicting results at last follow-up.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Wrist salvage procedures alter moment arms of the primary wrist muscles

BACKGROUND

Proximal row carpectomy and scaphoid-excision four-corner fusion are salvage procedures that relieve pain by removing arthritic joint surfaces. While numerous studies have examined how these procedures affect joint motion, few have examined how they influence muscle mechanical actions. This study examines whether muscle moment arms change after these procedures.

METHODS

Moment arms of primary wrist muscles were measured in 8 cadaveric specimens using the tendon excursion method. In each specimen, moment arms were measured for two degrees of freedom (flexion-extension and radial-ulnar deviation) and three conditions (nonimpaired, scaphoid-excision four-corner fusion, and proximal row carpectomy). For each muscle and degree of freedom, moment arm versus joint angle curves for the three conditions were statistically compared.

FINDINGS

Wrist salvage procedures significantly alter moment arms of the primary wrist muscles. Proximal row carpectomy primarily alters flexion-extension moment arms, while scaphoid-excision four-corner fusion primarily alters radial-ulnar deviation moment arms. Both procedures also alter the balance between agonist and antagonist wrist muscles. Following proximal row carpectomy, wrist extensors have smaller moment arms in extended postures. Following scaphoid-excision four-corner fusion, radial deviators have larger moment arms throughout radial-ulnar deviation.

INTERPRETATION

Different moment arms indicate that different forces are required to complete the same tasks in nonimpaired and surgically altered wrists. The altered muscle moment arms likely contribute to post-operative impairments. Understanding how salvage procedures alter muscle mechanical actions is a critical first step toward identifying the cause of post-operative impairments and is necessary to develop effective interventions to augment deficient muscles and improve overall function.

Application of a three-dimensional computational wrist model to proximal row carpectomy

A three-dimensional (3D) computational model of the wrist examined the biomechanical effects of the proximal row carpectomy (PRC), a surgical treatment of certain wrist degenerative conditions but with functional consequences. Model simulations, replicating the 3D bony anatomy, soft tissue restraints, muscle loading, and applied perturbations, demonstrated quantitatively accurate responses for the decreased motions subsequent to the surgical procedure. It also yielded some knowledge of alterations in radiocarpal contact force which likely increase contact pressure as well as additional insight into the importance of the triangular fibrocartilage complex and retinacular/capsular structures for stabilizing the deficient wrist. As better understanding of the wrist joint is achieved, this model could serve as a useful clinical tool.

Distal radius fracture after proximal row carpectomy

•

We encountered a patient with distal radius fracture (DRF) after proximal row carpectomy (PRC). The mechanism of the DRF after PRC is discussed in this report.

•

The DRF is needed wrist range of motion. Since the wrist range of motion decreased and the lunate fitted into the joint surface after PRC, making the forearm join with the hand like a single structure, pressure may have been loaded on the weak distal end of the radius from the dorsal side, causing volar displacement and fracture.

•

The pressure distribution and range of motion of the radiocarpal joint after PRC are different from those of a normal joint, and the mechanism of fracture also changes with it.

Introduction

We encountered a patient with distal radius fracture (DRF) after proximal row carpectomy (PRC). The mechanism of the DRF after PRC is discussed in this report.

Presentation of case

The patient was a 73-year-old female who had undergone PRC due to Kienböck disease before. The wrist range of motion was: 45° on dorsiflexion and 20° on flexion. DRF has occurred at 3 years after PRC. The fracture type was extra-articular fracture. Osteosynthesis was performed using a volar locking plate. No postoperative complication developed, the Mayo score was excellent at 6 months after surgery, and the daily living activity level recovered to that before injury.

Discussion

Since the wrist range of motion decreased and the lunate fitted into the joint surface after PRC, making the forearm join with the hand like a single structure, pressure may have been loaded on the weak distal end of the radius from the dorsal side, causing volar displacement and fracture.

Conclusion

The pressure distribution and range of motion of the radiocarpal joint after PRC are different from those of a normal joint, and the mechanism of fracture also changes due to PRC.

Salvage of a post-traumatic arthritic wrist using the scaphoid as an osteochondral graft

The authors describe a case of post-traumatic wrist arthritis with an osteochondral defect in the scaphoid fossa of the radius. The patient was treated with proximal row carpectomy, radial styloidectomy and reconstruction of the defect using the proximal half of the scaphoid as an autologous osteochondral graft. Pain relief was achieved while wrist motion and strength were improved. The carpal bones are a source of osteochondral grafts and can be used to expand the indications of motion-preserving wrist salvage procedures.

Two cases of pisiform bone impingement syndrome after proximal row carpectomy

Proximal row carpectomy (PRC) is an established surgical procedure used to treat post-traumatic osteoarthritis of the wrist with sparing of the midcarpal joint and advanced aseptic necrosis such as lunatomalacia. Proximalization of the distal carpal row following PRC may lead to secondary problems such as radiocarpal impingement. At follow-up, two of our patients complained about ulnar-sided wrist pain after proximal row carpectomy. Computed tomography (CT) scans were taken for both patients with an additional magnetic resonance imaging scan for one patient. The CT scan revealed clear osteolysis consistent with a pisiform bone impingement on the ulnar styloid process in both the cases, and also on the hamate in one patient. An impingement syndrome of this nature has not previously been described and should be kept in mind when patients report ulnocarpal symptoms after PRC.

Effect of capitate morphology on contact biomechanics after proximal row carpectomy

PURPOSE

Proximal row carpectomy (PRC) is used as a treatment for a variety of wrist pathologies to maintain motion and to improve strength and decrease pain. Several studies have looked at how PRC alters wrist characteristics, although they did not provide an explanation for the variability observed in outcomes. Studies have classified the capitate into 3 unique types: round, V-shaped, or flat. We hypothesized that these differences in morphology could affect the contact biomechanics between the radius and the capitate after PRC.

METHODS

A total of 14 cadaveric wrists underwent PRC. They were classified by capitate morphology and then loaded to 200 N in a neutral position, flexion, and extension. We measured contact area, contact pressure, and location using pressure-sensitive film in all 3 positions and compared their morphology types.

RESULTS

Nine wrists had a round-type capitate, 4 had a V-shaped capitate, and 1 had a flat capitate, which we excluded from statistical analysis. Comparing round and V-shaped types, we found no differences in contact area, pressure, or location in any wrist position For the V-shaped capitates, there was increased contact pressure in flexion and extension compared with the wrist in neutral. Center of pressure translated dorsal and radial in flexion to volar and ulnar in extension for all types.

CONCLUSIONS

When we compared V-shaped and round-type capitates, we found no significant differences in contact characteristics of the wrist after PRC. There were some differences in contact pressure for V-shaped capitates in various wrist positions.

CLINICAL RELEVANCE

Differences between round and V-shaped capitates do not appear to affect contact biomechanics after PRC. Thus, these 2 capitate shapes may not necessarily be a factor in the decision-making process to perform PRC.

Proximal row carpectomy

Proximal row carpectomy (PRC) is a motion-preserving treatment for the degenerated wrist. PRC provides painless wrist range of motion with few complications. PRC treats specifically scapholunate advanced collapse, scaphoid non-union advanced collapse, chronic perilunate dislocations, and Kienbock's disease. The best candidates are older than 35 with an intact capitate head and lunate facet of the distal radius. Proximal row carpectomy provides satisfactory postoperative wrist range of motion and grip strength with few complications, especially when there is no capitolunate arthrosis. Postoperative progressive changes at the radiocapitate articulation have been documented, yet these changes tend to remain asymptomatic.

Orientations of wrist axes of rotation influence torque required to hold the hand against gravity: a simulation study of the nonimpaired and surgically salvaged wrist

The wrist is a complex kinematic link connecting the forearm and hand. The kinematic design of the wrist is permanently altered during surgical salvage procedures, such as proximal row carpectomy (PRC) and scaphoid-excision four-corner fusion (SE4CF), which have the unintended consequence of long-term functional impairments to both the wrist and hand. We developed simulations of the nonimpaired, PRC, and SE4CF wrists to evaluate if surgically altered wrist kinematics contribute to functional impairments. Specifically, as a step toward understanding the connection between kinematics and function, we examined the torque necessary to statically maintain functional postures. All simulations included only bone geometry and joint kinematics; soft tissues were excluded. Our simulations demonstrate that the torque necessary to maintain a functional posture is influenced by the orientations of the flexion and deviation axes of rotation relative to each other and the anatomical planes of the radius. The magnitude of torque required to hold the hand against gravity decreased in simulations of the PRC wrist compared to the nonimpaired wrist. In contrast, the torque required increased relative to the nonimpaired wrist in simulations of the SE4CF wrist. These divergent results are directly related to how motion is coupled between the flexion-extension and deviation axes of rotation. This study highlights that, even without considering the effects of soft tissues, changing the kinematic design of the wrist influences function; therefore, kinematics should be considered when surgically redesigning the wrist.

Effectiveness of four-corner arthrodesis with use of a locked dorsal circular plate

BACKGROUND

Compared with traditional methods of fixation in four-corner arthrodesis, reviews of results using a dorsal circular plate (DCP) have identified higher complication rates. As the use of circular plate fixation for limited wrist arthrodesis was found to be a valuable concept per se and continued innovation and technical advancement are crucial to improve future treatment, changes in plate design were encouraged.

QUESTIONS/PURPOSES

To further evaluate the use of DCP fixation in four-corner arthrodesis, we report the first results using a radiolucent, nonmetallic (polyetheretherketone), locked DCP for four-corner arthrodesis.

METHODS

We retrospectively analyzed the clinical and radiographic results of 24 patients who underwent four-corner arthrodesis with a locked DCP at a minimum followup of 63 months (mean, 76 months; range, 63-91 months). There were nine women and 15 men, with a mean age of 53 years (range, 37-78 years) at the time of surgery. We evaluated ROM with a goniometer and grip strength with a dynamometer. Function was assessed using QuickDASH. Radiographs were evaluated for union, carpal alignment, and hardware problems.

RESULTS

At latest followup, ROM averaged 66% and 77% of the uninjured side in flexion-extension and radioulnar deviation, respectively. Grip strength averaged 70% of the uninjured side. The average postoperative QuickDASH score was 19.11. Union was achieved by 22 of the 24 patients.

CONCLUSIONS

Our data show four-corner arthrodesis with a radiolucent, nonmetallic, locked DCP is an effective procedure that allows stable primary fixation as a basis for good functional outcome, provided surgical technique and quality of bone graft are adequate.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Scapholunate instability: current concepts in diagnosis and management

Injuries to the scapholunate joint are the most frequent cause of carpal instability and account for a considerable degree of wrist dysfunction, lost time from work, and interference with activities. Although it is insufficient to cause abnormal carpal posture or collapse on static radiographs, an isolated injury to the scapholunate interosseous ligament may be the harbinger of a relentless progression to abnormal joint mechanics, cartilage wear, and degenerative changes. Intervention for scapholunate instability is aimed at arresting the degenerative process by restoring ligament continuity and normalizing carpal kinematics. In this review, we discuss the anatomy, kinematics, and biomechanical properties of the scapholunate articulation and provide a foundation for understanding the spectrum of scapholunate ligament instability. We propose an algorithm for treatment based on the stage of injury and the degree of secondary ligamentous damage and arthritic change.

Effects of proximal row carpectomy on wrist biomechanics: a cadaveric study

BACKGROUND

Many studies show good clinical results after proximal row carpectomy. Some biomechanical consequences are documented, but to our knowledge muscle moment arm variations have not previously been quantified.

METHODS

In five fresh-frozen wrist, kinematics and tendon excursions were measured using a 3D electrogoniometer and Linear Variable Differential Transformers (SOLARTRON Inc., AMETEK Advanced Measurement Technology, Inc, 801 South Illinois Avenue, Oak Ridge, TN 37831-2011, USA), respectively, in three conditions: intact wrist, after posterior capsulotomy and after proximal row carpectomy. Mean pivot point, defined as the point whose sum of the squared distances to the helical axes is minimum, wrist range of motion and mean moment arms were measured during dorso-palmar flexion, radioulnar deviation and circumduction movements.

FINDINGS

No alteration of the range of motion was observed. On the other hand, the mean pivot point shifted proximally (6.8-9.1mm) after proximal row carpectomy (p<0.05) for all motions tested and most muscle moment arms decreased significantly after proximal row carpectomy.

INTERPRETATION

The results of this study allow a better understanding of the biomechanical effects of this procedure. The important moment arm reduction and pivot point displacement suggest modifications of joint biomechanical parameters which could influence the functional outcome of PRC.

μCT-generated carpal cartilage surfaces: validation of a technique

Computational models are increasingly being used for the analysis of kinematics and contact stresses in the wrist. To this point, however, the morphology of the carpal cartilage has been modeled simply, either with non-dimensional spring elements (in rigid body spring models) or via simple bone surface extrusions (e.g. for finite element models). In this work we describe an efficient method of generating high-resolution cartilage surfaces via micro-computed tomography (μCT) and registration to CT-generated bone surface models. The error associated with μCT imaging (at 10 μm) was 0.009 mm (95% confidence interval 0.007-0.012 mm ), or ~1.6% of the cartilage thickness. Registration error averaged 0.33±0.16 mm (97.5% confidence limit of ~0.55 mm in any one direction) and 2.42±1.56° (97.5% confidence limit of ~5.5° in any direction). The technique is immediately applicable to subject-specific models driven using kinematic data obtained through in vitro testing. However, the ultimate goal would be to generate a family of cartilage surfaces that could be scaled and/or morphed for application to models from live subjects and in vivo kinematic data.

The arthritic wrist. I--the degenerative wrist: surgical treatment approaches

The primary goal in treating a degenerative wrist is to provide pain relief, while maintaining strength and mobility if possible. After failure of the recommended conservative treatment, the choice of approaches can be made from a large collection of techniques, some which are well validated. Partial wrist fusion, particularly the Watson procedure, results in a pain-free wrist in 80% of cases, with 50% of the mobility preserved, good grasping strength and stable results for at least 10 years. Proximal row carpectomy provides similar results if the cartilage on the head of the capitate is preserved and the patient is not involved in heavy manual labour. Complete denervation provides pain relief in almost 80% of cases while preserving motion and strength. This is a safe and effective option, with no age limit, that still allows other procedures to be performed in the future. Total wrist fusion also has its place in revision, and even as first-line treatment, because of the reliable outcome in terms of pain and strength, high satisfaction rates, little to no repercussions linked to the loss of mobility and fewer complications. Other techniques are now available. The partial or complete resection of a carpal bone and placement of an implant is back in vogue because of the availability of pyrocarbon. Such implants are an option in the future for localized osteoarthritis or even diffuse affections, and a useful alternative to more invasive procedures. The use of a rib cartilage graft to partially or completely replace a carpal bone or resurface the radius has promising results in terms of pain reduction and fusion. The role of total joint replacement must be defined relative to the classic, reliable techniques that have long-term outcome data.

LEVEL OF PROOF

IV.

Proximal row carpectomy: Is early postoperative mobilisation the right rehabilitation protocol?

PURPOSE OF THE STUDY

To determine the feasibility and interest of an early rehabilitation protocol with no initial immobilisation after proximal row carpectomy.

MATERIAL AND METHODS

Thirteen patients were included in this retrospective study. Range of motion (ROM) and wrist strength (grip strength and grasp strength) were evaluated 3 and 6 weeks after surgery on the both wrists (operated and non-operated). Postoperatively, patients had no immobilisation of the wrist, and began a rehabilitation program immediately after surgery in the department of Physical Therapy and Rehabilitation under multidisciplinary team supervision. The same surgical technique was used for all patients by the same surgeon.

RESULTS

Six weeks after PRC, there was a 25-51% deficit in passive ROM and 54-64% deficit in active ROM compared to the corresponding non-operated wrist. Six weeks after PRC, mean overall grip strength was nearly 55% and Jamar dynamometer grip strength was 51% of the contralateral side.

DISCUSSION

This study shows that immediate immobilisation following PRC is unnecessary, and that early rehabilitation is of the essence. Early rehabilitation could reduce the delay necessary to recover range of motion and strength, and probably the time to return to work.

LEVEL OF EVIDENCE

Level 4, prospective cohort study.

Biomechanics of the wrist after proximal row carpectomy in cadavers

We investigated the biomechanics of the radiocapitate joint after a proximal row carpectomy in six fresh-frozen cadaver wrists using super-low-pressure-sensitive film on a material testing system. The average pressure within the lunate fossa increased significantly from 23.2 to 136.4 N/cm(2) with a sharp decrease in the contact area from 2.08 to 0.30 cm(2) after a proximal row carpectomy. The cartilage of the proximal capitate had four sub-facets and therefore was not as smooth as the normal proximal lunate. We found that the wrist was overloaded after a proximal row carpectomy and the main cause was the anatomical mismatch of the radiocapitate articulation.

Proximal row carpectomy: long-term results

OBJECTIVES

To evaluate long-term clinical outcome of proximal carpectomy. Our assumption was that this intervention should result in long-term benefit, making a wrist painless, mobile, and functional, compatible with social and professional life, whatever the initial etiology of the degenerative wrist.

METHODS

We report a continuous single centre retrospective series of 24 patients. Objective (mobility, strength, radiographic evaluation) and subjective (pain, subjective wrist value, functional scores) functions were assessed by an independent observer. Surgery was performed mainly for Kienbock's disease, scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrists.

RESULTS

The follow-up lasted 116 months in average, during which pain was improved in all cases; 83% of the patients were satisfied with a mean score of 1.2 on a visual analogue scale (VAS) and 76% subjective wrist value (SWV) (disabilities of the arm, shoulder and hand [DASH]: 31). Wrist flexion-extension arc averaged 76 degrees , and the grip strength equivalent to 78% of the contralateral limb. Radiographic modification developed in 52% without any clinical impact. Three patients required arthrodesis and never felt comfortable with their carpectomy.

CONCLUSIONS

Our study shows a long-term efficacy of proximal row carpectomy. This treatment must be considered in the therapeutic arsenal for a degenerative and painful wrist, and it should no longer be regarded as a salvage procedure. Advantages of this intervention are obvious: technical simplicity, short rehabilitation, immediate functionality of the wrist and few complications.

Range of motion effects of distal pole scaphoid excision and triquetral excision after radioscapholunate fusion: a cadaver study

PURPOSE

Radioscapholunate (RSL) fusion is an effective surgical procedure for the treatment of isolated radiocarpal arthritis. Although functional wrist motion is typically preserved through the midcarpal joint, many patients are still frustrated by postoperative limitations. The purpose of this study was to evaluate motion of cadaver wrists after simulated RSL fusion with excision of the distal pole of the scaphoid and the triquetrum.

METHODS

Ten fresh-frozen cadaver upper extremities were mounted on a custom testing apparatus after isolation of the flexor carpi radialis, flexor carpi ulnaris, extensor carpi radialis longus, and extensor carpi ulnaris tendons. Sequential loading of these tendons resulted in flexion, extension, radial, and ulnar deviation. We subsequently measured range of motion with the use of digital photography. All specimens were tested in 4 states: intact (normal), RSL fusion (simulated), RSL fusion with distal scaphoid pole excision, and RSL fusion with distal scaphoid pole and triquetrum excision. The results were statistically analyzed using a repeated measures analysis of variance.

RESULTS

Range of motion decreased to 39% to 46% of normal for flexion and extension and 65% to 71% of normal for radial and ulnar deviation after simulated RSL fusion. The addition of distal pole of scaphoid excision resulted in flexion and extension returning to 72% to 79% of normal, and radial and ulnar deviation returning to 84% to 89% of normal. Excision of the triquetrum further increased flexion and extension to 87% to 97% of normal, and radial and ulnar deviation to 119% to 137% of normal.

CONCLUSIONS

The combination of triquetral and distal scaphoid pole excision after RSL fusion improves wrist motion to levels close to normal in the cadaver model.

Clinical evaluation of proximal row carpectomy revealed by follow-up for 10-29 years

To investigate the long-term clinical results of proximal row carpectomy for treating chronic wrist injuries, we collected the postoperative results of ten patients who underwent this procedure between 1978 and 1996. The evaluation was based on Gartland and Werley and modified Green and O'Brien scoring systems. The follow-up ranged from ten to 29 years. Nine patients could perform daily activities properly, two experienced occasional pain and one moderate pain. Eight patients were rated as excellent, two were good, while none was fair or poor by the former scoring system. Seven patients were rated as good, three were fair and none was excellent or poor by the latter scoring system. No apparent degenerative change was found in the radiocapitate joints apart from a slight change in one patient. The operation is a dependable and durable procedure that results in satisfactory pain relief, improved functional wrist motion and grip strength, allowing most patients to resume their previous work.

Proximal row carpectomy: role of a radiocarpal interposition lateral meniscal allograft

PURPOSE

The purpose of this study was to determine whether use of a lateral meniscal interposition allograft combined with proximal row carpectomy would reduce the peak joint contact pressures and increase the contact area when compared with proximal row carpectomy alone.

METHODS

Six cadaver wrists were cyclically moved through flexion-extension and radioulnar deviation ranges of motion. Joint contact pressure was measured with the carpus intact, after proximal row carpectomy, and after insertion of a lateral meniscal allograft. Contact pressure data were also collected with the wrist in 5 static positions.

RESULTS

Proximal row carpectomy caused statistically greater peak pressures and smaller contact areas when compared with the intact wrist. Insertion of the allograft statistically restored the pressures and areas to that observed in the intact wrist.

CONCLUSIONS

These results support the clinical trial of a lateral meniscal interposition allograft in patients with contraindications for proximal row carpectomy, such as pre-existing arthritis in the capitate head or lunate facet of the radius.