Distal scaphoid resection arthroplasty for the treatment of degenerative arthritis secondary to scaphoid nonunion

Long-Term Oral Steroid Use: A Unique Risk Factor in 4-Corner Fusion Compared With Other Wrist Salvage Operations

INTRODUCTION

Salvage procedures such as proximal row carpectomy, 4-corner fusion, total wrist arthroplasty, and total wrist arthrodesis are commonly used at the end stages of wrist arthritis. These operations have high complication rates, and significant controversy exists regarding the selection of procedure. Long-term oral glucocorticoid therapy has previously been identified as a risk factor for complications in multiple orthopedic procedures. The purpose of this study is to investigate the effect long-term oral preoperative corticosteroid use has on complications after different salvage operations for wrist arthritis.

METHODS

The National Surgical Quality Improvement Program database was queried to identify patients who underwent proximal row carpectomy, 4-corner fusion, total wrist arthroplasty, or total wrist fusion between 2005 and 2020. Patients were classified by steroid use. Univariate analysis and multivariate logistic regression were used to assess the risk of complications.

RESULTS

A total of 1298 patients were identified. Overall, steroid use was found to be independently associated with a higher complication rate. On multivariate analysis of patients who underwent 4-corner fusion, steroid use was found to be associated with higher complication rate and surgical site infection rate. Steroid use was not associated with increased complications in patients who underwent proximal row carpectomy, total wrist arthroplasty, or total wrist fusion when examined individually.

CONCLUSION

Long-term oral corticosteroid therapy was associated with an increased risk of postoperative infections in patients who underwent 4-corner fusion, which was not found in other wrist salvage operations.

How Much Scaphoid Can be Safely Resected? A Biomechanical Analysis of the Effects of Distal Scaphoid Resection

BACKGROUND

Resection of the distal pole of the scaphoid has been advocated as a simple alternative to other wrist salvage procedures for scaphoid nonunion advanced collapse and scaphotrapezio-trapezoid arthritis. However, the extent of scaphoid that may be resected without adversely affecting carpal kinematics has never been clearly defined.

METHODS

Seven cadaveric upper extremities were tested in a custom motion wrist simulator. A 3-stage sequential sectioning of the distal scaphoid protocol was performed in 25% increments then cyclic active wrist flexion-extension and dart thrower's motion trials were recorded.

RESULTS

The extent of distal scaphoid resection had no effect on overall wrist range of motion. The lunate assumed a more extended position following resection of the distal scaphoid compared to intact. At 25%, 50%, and 75% of distal scaphoid resection, the lunate extended to 13.32° ± 9.4°, 23.43° ± 7.5°, and 15.81° ± 16.9°, respectively. The capitate migrated proximally with 25% and 50% distal scaphoidectomy, and proximally and radially with 75% of the scaphoid resected. Resection of 75% of the scaphoid resulted in unstable wrist kinematics.

CONCLUSIONS

Resection of up to 25% of the distal scaphoid did not significantly influence carpal kinematics and induced mild lunate extension deformity. Resection of 50% of the scaphoid induced further and potentially clinically significant lunate extension and dorsal intercalated segment instability. Further removal of 75% of the distal scaphoid induced capitate migration radially and unpredictable wrist kinematics. Consequently, removal of over 25% of the scaphoid should be avoided or supplemented with partial wrist fusion.

Surgical management of osteoarthritis of the hand and wrist

Osteoarthritis of the hand and wrist is common; varying disease manifestations and a spectrum of symptoms make it imperative to approach treatment strategies in an individualized fashion. In this review, attention is focused upon site specific diagnoses and indications for various surgical treatment strategies.

Management of scapholunate advanced collapse and scaphoid nonunion advanced collapse without proximal row carpectomy or four corner fusion

Four corner arthrodesis and proximal row carpectomy are the most common techniques for the management of advanced radiocarpal arthritis due to longstanding scapholunate instability and scaphoid nonunion. The advantages and short comings of each technique have been well defined in the literature. Advancements in joint replacement and arthroscopic surgery have resulted in new operations to manage radiocarpal and midcarpal arthritis. Most of these new procedures are modifications of the two classical operations, but some use modern implants and newer materials. New individualized options, like osteochondral grafting in combination with proximal row carpectomy or (arthroscopic) distal resection of the scaphoid, allowed us to improve our treatment and offer patients less invasive but equally effective procedures. We consider that four corner arthrodesis and proximal row carpectomy should not always be standard management for advanced radiocarpal arthritis.

Trapeziometacarpal Fusion With and Without Distal Scaphoid Excision: A Cadaveric Model Comparing Thumb Range of Motion

Purpose: To describe the biomechanical changes seen after thumb carpometacarpal (CMC) fusion with distal scaphoid excision (DSE), a surgical technique used for pantrapezial disease in high-demand individuals. Methods: A cadaveric study with 13 fresh-frozen cadaveric specimens was conducted. Fluoroscopic measurements in posteroanterior (PA) and lateral planes were performed. Thumb CMC fusion was then simulated. The same images were taken after fusion. The distal scaphoid was excised, and the measurements were obtained again. The angle between the index finger and thumb metacarpals was recorded. Statistical analysis was performed using Wilcoxon signed rank test. Results: The mean arcs of motion in the PA plane pre-fusion, post-fusion, and post-fusion with DSE were 48.5°, 25.1°, and 34.6°, respectively. An increase in arc of 9.5° was obtained after DSE compared with thumb CMC fusion alone. The mean arcs of motion in the lateral plane pre-fusion, post-fusion, and post-fusion with DSE were 53.4°, 22.4°, and 33.6°, respectively. A statistically significant increase in arc of motion of 11.2° in the lateral plane was obtained after DSE compared with thumb CMC fusion alone. This was a 20% and 21% increase in pre-fusion range of motion in the PA and lateral planes, respectively, from fusion alone compared with fusion and DSE. Conclusions: Thumb CMC fusion combined with DSE maintains motion lost in simple CMC arthrodesis.

Effect of Partial and Complete Trapezoid Excision on Radiographic and Functional Results After Abductor Pollicis Longus Suspensionplasty

PURPOSE

We hypothesized that adding complete or partial trapezoid excision is associated with greater radiographic carpal collapse and worse functional outcomes compared with a simple trapeziectomy and abductor pollicis longus suspensionplasty.

METHODS

A total of 69 patients had abductor pollicis longus suspensionplasty (79 hands), 87% of whom were female, mean age 64 years. Scaphotrapezium-trapezoid arthritis noted at surgery was treated with an additional proximal trapezoid excision (PT) in 21 (27%) or complete trapezoid resection (CT) in 22 hands (28%). No trapezoid was excised in 36 hands. The primary outcome was final radiolunate (RL) extension of 15° or greater on lateral radiographs. Logistic regression (for change in RL angle) and linear regression (for continuous variables) with robust variance estimate to account for within-subject correlation (generalized estimating equation method) were used to investigate whether the trapezoid excision groups had an effect on the outcomes of interest. Models were adjusted for age and sex.

RESULTS

Median follow-up was 92 months. Complete trapezoid resection had the most increase in RL angle, but PT had a higher incidence (29% vs 26%) of final RL angle of 15° or greater compared with CT. When stratified into groups with a final RL greater than or less than 15°, the former group had worse total function (Patient-Rated Wrist Evaluation) and Quick-Disabilities of the Arm, Shoulder, and Hand scores. Symptomatic index metacarpal migration was seen in 4 CT and 2 PT wrists (18% and 10%, respectively) and was considered to indicate failure.

CONCLUSIONS

Compared with no trapezoid excised, both PT and CT had a greater incidence of lunate extension of 15° or greater, consistent with radiographic nondissociative-dorsal intercalated carpal instability, which was associated with inferior functional scores. Symptomatic proximal collapse of the index metacarpal was seen in both CT and PT. Further studies should evaluate whether routine excision of the proximal trapezoid is necessary for scaphotrapezoid arthritis, because any disruption of the scaphotrapezoid ligament complex appears to increase risk for developing carpal instability nondissociative-dorsal intercalated carpal instability over time and may be associated with inferior functional results. Complete trapezoid excision is not recommended.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

The Biomechanical Consequences of Trapeziectomy and Partial Trapezoidectomy in the Treatment of Thumb Carpometacarpal and Scaphotrapeziotrapezoid Arthritis

PURPOSE

To determine, using a biomechanical cadaveric model, whether, in the treatment of thumb carpometacarpal and scaphotrapeziotrapezoid arthritis, partial trapezoid resection following trapeziectomy causes carpal, specifically lunocapitate and scapholunate, instability.

METHODS

Eight fresh-frozen mid-forearm cadaver specimens with type I lunates and devoid of basilar thumb arthritis were used in the study. Specimens were mounted onto a wrist simulator applying cyclical wrist flexion/extension and radial/ulnar deviation motions. Carpal kinematics, specifically lunocapitate and scapholunate joint relationships, were measured at 4 different conditions: (1) a native intact state, (2) after trapeziectomy, (3) after 2-mm partial trapezoid resection, and (4) after 4-mm partial trapezoid resection.

RESULTS

During both flexion/extension and radial/ulnar deviation of the wrist, the lunocapitate and scapholunate joint relationship did not show any notable change following any of trapeziectomy, 2-mm, or 4-mm trapezoid resection compared with the intact state. Changes to the lunocapitate and scapholunate angles were clinically insignificant-a maximum of 6° and 4° change, respectively.

CONCLUSIONS

This biomechanical cadaveric study shows that performing a trapeziectomy followed by up to 4 mm of proximal trapezoid resection has a negligible effect upon carpal, specifically lunocapitate and scapholunate, stability. Further research is needed to elucidate the long-term clinical consequences of limited trapezoid resection in vivo.

CLINICAL RELEVANCE

There may be no clinically relevant effects of resection of up to 4 mm of trapezoid in the surgical management of combined basilar thumb and scaphotrapeziotrapezoid arthritis.

Distal Scaphoid Excision in Treatment of Symptomatic Scaphoid Nonunion: Systematic Review and Meta-analysis

Background: Current treatment options for persistent scaphoid nonunion are limited to salvage procedures such as proximal row carpectomy (PRC) or 4-corner fusion (4CF). Several small studies have demonstrated that distal scaphoid excision may provide a simpler alternative with faster recovery. The purpose of this study was to determine the efficacy of distal scaphoid excision as a treatment option for symptomatic scaphoid nonunion. Methods: The MEDLINE and PubMed databases were searched for the use of distal scaphoid excision in scaphoid nonunions. Studies included reported on either the functional or patient-centered outcomes following distal scaphoid excision for symptomatic scaphoid nonunion. Results: Six articles described the outcomes of 70 patients with an average of 11.7 patients per study. Functional outcomes including flexion-extension arc, radial-ulnar deviation, and grip strength improved by an average of 98.95%, 58.96%, and 131.08%, respectively. Patient-derived outcomes included the Modified Mayo Wrist Score, which improved by 92.6%, and the Disabilities of the Arm, Shoulder and Hand, which improved by 137.17%. An average of 68.75% of patients experience complete relief of pain with 20.83% of patients experiencing pain with strenuous activity. The average postoperative visual analog scale (0-10) was 0.71. On average, 93.33% of patients returned to work with an average time of return being 6.89 weeks. Complete satisfaction was reported by 87.80% of patients. Complications included progression into 4CF or PRC and newly developed midcarpal arthritis. Conclusions: Given favorable outcomes, our analysis suggests that distal scaphoid excision may be a favorable, low-risk treatment for scaphoid nonunion without eliminating more extensive options such as 4CF and wrist arthrodesis.

The Effect of Lunate Morphology in Carpal Disorders: Review of the Literature

Variation in lunate morphology can exist based on the absence (Type I) or presence (Type II) of medial facet on the distal articular surface of the lunate that contacts the proximal pole of the hamate. This additional lunatohamate articulation can affect load transmission across the radiocarpal joint and exert an influence on carpal kinematics. A Type II lunate is protective against carpal instability patterns associated with scaphoid nonunions and scapholunate dissociations. It may also play a role in the progression of carpal collapse that occurs in Kienböck disease. This review summarizes the effect of lunate morphology in the outcomes of non-operative and operative treatment of carpal disorders.

Distal Pole Resection of the Scaphoid for the Treatment of Scaphotrapeziotrapezoid Osteoarthritis

BACKGROUND

Distal pole resection of the scaphoid is one of the surgical techniques applied for the treatment of painful scaphotrapeziotrapezoid osteoarthritis (STT-OA).

METHODS

In this retrospective study, we evaluated midterm outcomes in a consecutive series of patients who underwent distal pole resection of the scaphoid: 13 patients (15 wrists) with a mean follow-up of 4.1 years. We examined objective functional and patient-reported outcome measures. In addition, we assessed the degree of dorsal intercalated segment instability (DISI) and postoperative complications.

RESULTS

All patients scored within a normal range on objective functional and patient-reported outcome measures. We observed a mild postoperative DISI deformity with an average lunocapitate angle of 22° (range, 0°-44°), which did not correlate with pain scores. In the opposite wrists, with and without STT-OA, the average lunocapitate angle was 6° (range, 0°-20°).

CONCLUSIONS

According to this study, midterm results for distal pole resection of the scaphoid are satisfactory.

Surgical Strategy for Scaphoid Nonunion Treatment

Scaphoid fracture is the most common carpal fracture. Nonunion rate has been reported around 10 to 15% of scaphoid fractures. Risk factors for scaphoid nonunion are known as location, displacement, poor vascularity, time to treatment etc. The goals of surgical treatment for scaphoid nonunion are to achieve bony union, to correct carpal deformities and also to prevent progressive carpal instability and arthritis. Scaphoid nonunion can cause scaphoid nonunion advanced collapse (SNAC) which is a pattern of progressive degenerative radiocarpal and midcarpal arthritis secondary to posttraumatic pathomechanics of the scapholunate joint. Achieving bony union is essential to prevent carpal collapse or arthritis. To improve bony union, many surgical procedures including various forms of bone grafting have been developed and attempted. However, there is a controversy about which procedure is the most effective. In this review, we provide an overview of surgical treatment methods for scaphoid nonunion and discuss proper surgical strategies for scaphoid nonunion which requires surgical management.

Scaphoid Fractures: Nonunion and Malunion

The treatment of scaphoid nonunion and malunions has undergone a considerable transition since the 1960 modification of Matti's technique by Russe.¹ We present a review of articles with clear data on union rates and functional status to review the current methods of treatment for scaphoid nonunion and malunion.

Distal scaphoid resection for degenerative arthritis secondary to scaphoid nonunion: a 20-year experience

PURPOSE

To evaluate the long-term results of distal scaphoid excision for degenerative arthritis secondary to scaphoid nonunion and compare them with our original results published in 1999.

METHODS

Nineteen patients who were treated by distal scaphoid resection arthroplasty from 1987 through 2010 were included. The mean follow-up was 15 years (range, 10-25 y) vs 4 years in the previous study. Clinical evaluation included measurement of the visual analog pain scale, wrist range of motion, and grip strength. Radiographs were taken at follow-up to assess for signs of arthritis and wrist collapse.

RESULTS

The outcomes of this procedure include increased grip strength and total arc of motion, a small decrease in revised carpal height ratio, and a small increase in radiolunate angle. Two patients failed distal scaphoid resection arthroplasty necessitating proximal row carpectomy (1) and wrist arthrodesis (1) for recalcitrant pain. More than half of the remaining patients developed midcarpal arthritis on radiographs that was asymptomatic. No patients developed radiolunate arthritis.

CONCLUSIONS

This study showed that distal scaphoid resection arthroplasty produced favorable, long-term clinical results and did not result in noteworthy wrist collapse. Midcarpal arthritis, which may develop after the procedure, did not cause appreciable deterioration in patient outcomes. This procedure also did not eliminate the option of using additional, more conventional reconstructive procedures if needed.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Reproducibility of radiographic classification of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist

The aim of this study was to measure inter- and intra-observer agreement on the radiographic classification of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist. Radiographs of 41 patients with SLAC wrist and 47 patients with SNAC wrist were graded on two separate occasions by four orthopaedic consultants specializing in hand and wrist surgery. Inter-observer agreement was evaluated using the multi-rater kappa value. Landis and Koch criteria were used to assess the level of agreement. Intra-observer agreement was tested by re-grading the radiographs after an interval of 2 to 4 weeks and calculating the weighted kappa value. For SLAC wrist, the inter-observer agreement was moderate (kappa value = 0.59) and intra-observer agreement substantial (kappa value = 0.65). For SNAC wrist, the inter-observer agreement was slight (kappa value = 0.20) and intra-observer agreement was fair (kappa value = 0.29). Radiographic classification of SLAC wrist has moderate reliability and reproducibility, whereas classification of SNAC wrist has limited reliability.

Scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist arthritis

Scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) are the two most common patterns of posttraumatic wrist arthritis. This review discusses the etiology and clinical evaluation, as well as up-to-date treatment options, for both of these conditions. Classic as well as newer innovative techniques are discussed with clinical outcomes in order to provide an evidence-based review of the world's literature on SLAC/SNAC wrist.

Midcarpal hemiarthroplasty for wrist arthritis: rationale and early results

Midcarpal hemiarthroplasty is a novel motion-preserving treatment for radiocarpal arthritis and is an alternative to current procedures that provide pain relief at the expense of wrist biomechanics and natural motion. It is indicated primarily in active patients with a well-preserved distal row and debilitating arthritic symptoms. By resurfacing the proximal carpal row, midcarpal arthroplasty relieves pain while preserving the midcarpal articulation and the anatomic center of wrist rotation. This technique has theoretical advantages when compared with current treatment options (i.e., arthrodesis and total wrist arthroplasty) since it provides coupled wrist motion, preserves radial length, is technically simple, and avoids the inherent risks of nonunion and distal component failure. The KinematX midcarpal hemiarthroplasty has an anatomic design and does not disrupt the integrity of the wrist ligaments. We have implanted this prosthesis in nine patients with promising early results. The indications for surgery were as follows: scapholunate advanced collapse wrist (three), posttraumatic osteoarthritis (three), inflammatory arthritis (two), and Keinböck disease (one). Prospective data has been collected and the results are preliminary given the infancy of the procedure. The mean follow-up was 30.9 weeks (range: 16 to 56 weeks). The mean Mayo wrist score increased from 31.9 preoperatively to 58.8 (p < 0.05) and the mean DASH score improved significantly from 47.8 preoperatively to 28.7 (p < 0.05). There was a trend toward increased motion but statistical significance was not reached. Two patients required manipulation for wrist stiffness. There was no evidence of prosthetic loosening or capitolunate narrowing. The procedure is simple (average surgical time was 49 minutes) and maintains coupled wrist motion through preservation of the midcarpal articulation. The preliminary data show that it appears safe but considerably longer follow-up is required before conclusions can be drawn as to its durability, reliability, and overall success. The level of evidence for this study is therapeutic level IV (case series).

Scaphoid nonunion and distal fragment resection: analysis with three-dimensional rigid body spring model

BACKGROUND

Distal fragment resection is one of the salvage procedures for scaphoid nonunion with osteoarthritis. Despite being reported as a simple procedure with favorable midterm outcomes, further arthritic changes remain a concern in the long term. Scaphoid waist fracture is classified into volar or dorsal types according to the displacement pattern, but the indications for distal fragment resection have never been discussed for these fracture types.

METHOD

We reconstructed a normal wrist model from computed tomography images and performed theoretical analysis utilizing a three-dimensional rigid body spring model. Two types of scaphoid fracture nonunion followed by distal fragment resection were simulated.

RESULTS

With volar-type nonunion, the force transmission ratio of the radiolunate joint increased, and the pressure concentration was observed in the dorsal part of the scaphoid fossa and volar part of the lunate fossa of the radius; no deterioration was seen in the midcarpal joint. In the distal fragment resection simulation for volar-type nonunion, pressure concentrations of the radiocarpal joint resolved. With dorsal-type nonunion, force transmission ratio in the radiocarpal joint resembled that of the normal joint model. Pressure concentrations were observed in the dorsoulnar part of the scaphoid fossa and radial styloid. The pressure concentration in the dorsoulnar part of the scaphoid fossa disappeared in the resection model, whereas the concentration in the radial styloid remained. In the midcarpal joint, pressure was concentrated around the capitate head in the nonunion model and became aggravated in the resection model.

CONCLUSIONS

With volar-type scaphoid nonunion, distal fragment resection seems to represent a reasonable treatment option. With dorsal-type nonunion, however, pressure concentration around the capitate head was aggravated with the simulated distal fragment resection, indicating a potential risk of worsening any preexisting lunocapitate arthritis.

Carpal osteoarthrosis

Despite improved understanding of carpal mechanics, increased awareness of intercarpal ligament injuries, and improved techniques for treating carpal instability, post-traumatic intercarpal osteoarthrosis remains a common problem. Osteoarthritis of the carpal bones, including scapholunate advance collapse wrist, scaphotrapeziotrapezoid arthritis, lunotriquetral arthritis, triquetrohamate arthritis, and pisotriquetral arthritis, follows specific unique patterns, but in each, the final common pathway leads to degenerative change. Injury or deformity leads to instability and altered kinematics, producing abnormal joint contact pressures. Cartilage injury and eventual degeneration of the join follow. The etiology, prevalence, and current evaluation and treatment of these conditions are of importance to hand surgeons.

Scaphoid fractures and nonunions: diagnosis and treatment

BACKGROUND

Scaphoid fractures are commonly seen in orthopedic practice. An organized and thoughtful approach to diagnosis and treatment can facilitate good outcomes. However, despite optimal treatment, complications may ensue. In the setting of nonunion or an avascular proximal pole, vascularized bone grafting may be needed.

METHODS AND RESULTS

In this article we review the literature regarding these injuries and describe an approach to diagnosis, treatment, and management of scaphoid fractures and nonunions.

CONCLUSION

Scaphoid fractures and nonunions may present as challenging problems in practice, but a systematic and deliberate approach can facilitate optimal results.

Distal scaphoid resection arthroplasty for scaphoid nonunion with radioscaphoid arthritis

The authors compare the functional outcome of 8 patients treated by distal scaphoid resection arthroplasty for scaphoid nonunion with symptomatic wrist arthritis before surgery and after a minimum follow-up of 6 months. There was a significantly better range of radial deviation and grip strength at the time of re-examination. Significantly fewer patients complained of resting pain. By contrast the change of radiolunate angle measured before the surgery and at the time of re-examination was statistically insignificant. Our preliminary results show that distal scaphoid resection arthroplasty seems to be a useful treatment method of scaphoid nonunion with symptomatic wrist arthritis.

Arthrose radioscaphoïdienne traitée par autogreffe ostéocartilagineuse après résection proximale du scaphoïde

PURPOSE OF THE STUDY

Radioscaphoid osteoarthritis is usually a complication of scaphoid pseudarthrosis or chronic scapholunate disjunction. As an alternative to the classical surgical techniques used for this lesion, we propose a novel reconstruction method consisting In partial proximal resection of the scaphoid associated with interposition of a biological spacer composed of a osteocartilaginous rib graft. The purpose of this study was to present the technical aspects of this procedure and to report preliminary results in ten patients with radioscapular osteoarthritis treated between 1994 and 2001.

MATERIAL AND METHODS

We performed a retrospective analysis of the ten patients who underwent surgery from 1994 to 2001 for early-stage radioscaphoid osteoarthritis associated with scaphoid osteoarthritis in eight and chronic scapholunate disjunction in two. The procedure consisted in partial resection of the proximal portion of the scaphoid and insertion of an osteocartilaginous autograft harvested from a rib. Outcome was based on the clinical results (pain, motion, grip force, activity) and patient satisfaction. Bone healing was measured with plain x-rays and vitality of the osteocartilaginous graft with MRI.

RESULTS

Mean follow-up was 4.6 years. Clinical outcome was considered excellent or good in eight patients, fair in one and poor in one (graft dislocation). All patients were satisfied or very satisfied except one (one failure). Radiological healing was achieved at three months in nine patients. Four patients underwent an MRI examination at thirteen months which demonstrated, in all patients: no sign of necrosis, healing of the graft-scaphoid interface, and no bony metaplasia in the cartilage.

DISCUSSION

Compared with partial carpal arthrodesis and resection of the first row of the carpus, this palliative technique can be used to reconstruct the proximal portion of the carpal scaphoid in young patients with early-stage radioscaphoid osteoarthritis. As for arthroplasty or scaphoid implants, our goal was to achieve a satisfactory scaphoid height using a biological spacer after resection of the proximal 3/4 of the bone. The results of this technique are encouraging but must be examined with precaution due to the small number of patients and the short follow-up to date.

Scaphoid nonunion: diagnosis and treatment

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the anatomy and pathophysiology of scaphoid fractures. 2. Understand the risk factors for scaphoid nonunion. 3. Identify treatment options for scaphoid nonunion and their respective advantages and disadvantages. 4. Identify salvage procedures for scaphoid nonunion advanced collapse of the wrist. Scaphoid nonunion is a common but difficult problem for hand surgeons. The diagnosis of scaphoid nonunion is often delayed, and therefore, treatment must be tailored to the type of fracture, the duration of nonunion, and the presence or absence of resulting arthritis. This article reviews the diagnosis and work-up of scaphoid nonunion, classification schemes for scaphoid nonunion, and various treatment options, including internal fixation, nonvascularized and vascularized bone grafting, and salvage procedures.

Management of scaphoid nonunions

Scaphoid nonunions result in a predictable pattern of wrist arthrosis. To minimize the incidence of arthrosis, the goal of treatment should be consolidation of the fracture with the scaphoid in anatomic alignment. Computed tomography and magnetic resonance imaging scans can aid evaluation of carpal collapse, scaphoid collapse, scaphoid nonunion, bone loss, and detection of osteonecrosis. Nonunion of the scaphoid waist may result in a humpback deformity, increasing the chances of further collapse and arthrosis. This collapse deformity must be approached volarly with an intercalary bone graft and internal fixation. A dorsal approach to proximal scaphoid nonunions allows easier access for removing the necrotic bone from the proximal pole and applying accurate screw or pin fixation. Vascularized bone graft is recommended to manage scaphoid nonunions with osteonecrosis.

The radial portal for scaphotrapeziotrapezoid arthroscopy

The scaphotrapeziotrapezoidal (STT) joint is a complex joint in which the arthroscope and instruments can be used through the radial midcarpal and STT-ulnar portals. This report describes a new arthroscopic portal at the STT joint to complete and improve the evaluation and treatment of this joint by arthroscopy: The STT-radial (STT-R) portal is situated immediately radial to the abductor pollicis longus at the STT level. Five cadaveric wrist specimens were dissected immediately after the portal was established, and photographed to determine the proximity of neurovascular structures. Magnetic resonance imaging evaluation of 15 hands was performed to measure the proximity of the radial artery. A cadaveric distal scaphoid excision was also created arthroscopically to show the real usefulness of this portal. Results of the anatomic study showed that no lesions of nerves or vessels were seen at this portal. Magnetic resonance imaging showed that the radial artery was located at a safe distance from the portal. The distal scaphoid excision was performed 15 minutes after the STT portals were established. Our results suggest that this new portal is safe and effective.