Results of a method of 4-corner arthrodesis using headless compression screws

A Novel Technique of Arthroscopic-Assisted Four-Corner Fusion and Robot-Assisted Fixation for Scaphoid Nonunion Advanced Collapse Wrist: A Single Case Study

OBJECTIVE

Scaphoid nonunion advanced collapse (SNAC) is a relatively common and debilitating wrist disorder yet its treatment remains challenging and controversial. We aim to describe a novel technique of a dual arthroscopic and robotic assisted four-corner fusion (4CF) in the treatment of SNAC wrist.

METHODS

In this study, we describe an original arthroscopic and robotic assisted 4CF, which is novel and currently unpublished in literature. The surgical approach included these predefined steps: arthroscopic resection of the scaphoid, radial styloid and of diseased cartilage between the capitate-lunate joint and triquetrum-hamate joint, correction of Dorsal Intercalated Segment Instability (DISI) deformity of the wrist and robotic assisted 4CF performed percutaneously with screws. Dynamic fluoroscopic imaging with the mini C-arm was performed five times and the 3D scanning machine was used once.

RESULTS

Our patient with SNAC II wrist was 57 years old at the time of initial presentation with a history of untreated traumatic wrist injury approximately 20 years ago. Regular wrist X-rays were performed at the outpatient setting and a computed tomography (CT) of the wrist was performed at the third postoperative month to confirm bony union. The patient's wrist range of motion (ROM), grip strength, Visual Analog Scale (VAS) score, Quick Disabilities of Arm, Shoulder, and Hand (QuickDASH) score, Modified Mayo Wrist Score (MMWS), and Patient Rated Wrist Evaluation (PRWE) were also evaluated during short-term follow-up at 6 months. During the patient's review at 6 months, his VAS score was 0 with complete pain relief. His wrist flexion was 20° and wrist extension at 45°. His pronation-supination was normal and comparable to his uninjured contralateral wrist. His operated wrist which was also his dominant hand had a grip strength of 22 kg as compared with 28 kg of the unaffected hand. He also had a Mayo Wrist Score of 85, QuickDASH score of 2.3 and PRWE of 6, and resumed his occupation as a clerk at 3 months.

CONCLUSIONS

This dual arthroscopic and robotic assisted 4CF is a novel surgical method worth considering in the treatment of SNAC II wrists. It is minimally invasive and allows for accurate placement of the screws in a single attempt. There was bony union by the third postoperative month as confirmed by CT imaging and excellent resolution of symptoms.

Treatment Outcomes of All Arthroscopic 4-Corner Arthrodesis Techniques With 2 Headless Screws

PURPOSE

Scaphoid excision with 4-corner arthrodesis is a safe procedure that relieves pain while also preserving the functional movements of the wrist. Different techniques have been described with successful results. In this study, we present the midterm clinical outcomes of 17 patients who underwent treatment with our arthroscopic 4-corner arthrodesis technique.

METHODS

Patients with at least 1 year of follow-up were included in our study. Preoperative and postoperative radiologic, functional, and clinical results were compared. Radiologic and clinical union were achieved in all patients.

RESULTS

Significant improvement was observed in Quick Disabilities of the Arm, Shoulder, and Hand, Mayo Wrist Score, visual analog scale, and Patient-Rated Wrist Evaluation scores. Although wrist range of motion increased in the radioulnar plane, no clinically important change was observed in the flexion-extension arc. The patients were able to return to work in an average of 10 weeks.

CONCLUSIONS

The arthroscopic 4-corner arthrodesis technique is a method with satisfactory outcomes. The main disadvantage of this procedure is that it requires a lengthy operative time, and both specific expertise and equipment.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Limited intercarpal fusion versus proximal row carpectomy in the treatment of SLAC or SNAC wrist, results after 3.5 years

The present study compares the postoperative clinical, radiological, and patient-reported functional results between the surgical procedures Proximal Row Carpectomy and Limited Carpal Fusion, in the treatment of SLAC and SNAC conditions of the wrist. 15 Proximal Row Carpectomy patients and 45 Limited Carpal Fusion patients were included in the study. Postoperative outcomes were assessed and compared for pain at load, range of motion, grip strength, Quick-DASH, and satisfaction. A radiological assessment was performed at the follow-up. The Proximal Row Carpectomy patients had a mean age of 60 years (range 31-77) and a mean follow-up of 42 months. The Limited Carpal Fusion patients had a mean age of 58 years (range 35-76) and a mean follow-up of 41 months. The patients treated with Limited Carpal Fusion performed significantly better regarding pain, radial-ulnar motion, and the Quick-DASH (p = 0.002, p = 0.003, and p = 0.002), respectively. The grip strength difference between the treatment groups was stratified for gender and was found significantly better for men in the LCF-treated patients, but not different for women (p = 0.03, p = 0.26), respectively. Differences in flexion-extension between the groups were insignificant (p = 0.525). A higher conversion rate to total wrist fusion was observed in the patients treated with the Proximal Row Carpectomy. All the Proximal Row Carpectomy patients had osteoarthritis at follow-up, whereas it was seen in 19% of the Limited Carpal Fusion patients. The patient-reported satisfaction was substantially better for the Limited Carpal Fusion patients. In conclusion, among patients treated for SNAC and SLAC wrist conditions, besides the findings of flexion-extension, and grip strength which were found without difference for women the findings are in favour of Limited Carpal Fusion compared to Proximal Row Carpectomy. Further, preferably prospective studies are needed to confirm or reject our findings.Level of evidence: Retrospective, comparative cohort study, level III.

Proximal ROw carpectOmy versus four-corner Fusion (PROOF-trial) for osteoarthritis of the wrist: study protocol for multi-institutional double-blinded randomized controlled trial

BACKGROUND

Scapholunate advanced collapse (SLAC) and scaphoid non-union advanced collapse (SNAC) are common types of wrist osteoarthritis (OA). Non-operative treatment consists of pain medication, splinting, and avoiding activities that induce pain. However, in case a course of conservative treatment is unsuccessful, operative treatment is needed. The two most conventional operative approaches for SLAC/SNAC OA are four-corner arthrodesis (FCA) and proximal row carpectomy (PRC). Although FCA is the gold-standard operative technique and may lead to superior grip strength, the evident benefit of PRC is that it obviates any need for hardware removal and controlling for bony union. To date, no high-quality randomized controlled trial comparing FCA and PRC exists. As clinical outcomes seem comparable, a trial that assesses patient-reported outcomes, adverse events, and secondary operations may guide clinical decision making between these two procedures. Thus, the aim of this multi-institutional double-blind randomized controlled trial is to study whether PRC is non-inferior to FCA in treating SLAC/SNAC OA. We hypothesize that PRC is non-inferior to FCA with lower economic expanses.

METHODS

The trial is designed as a randomized, controlled, patient- and outcome-assessor blinded multicenter, two-armed 1:1 non-inferiority trial. Patients with SLAC/SNAC-induced wrist pain meeting trial inclusion criteria will undergo wrist arthroscopy to further assess eligibility. Each patient eligible for the trial will be randomly assigned to undergo either FCA or PRC. The primary endpoint of this study is the Patient Rated Wrist Evaluation (PRWE) at 1-year after FCA versus PRC. Secondary outcomes include Quick-Disabilities of the Arm, Shoulder and Hand, EQ-5D-5L, pain, grip strength, wrist active range of motion, radiographic evaluation, and adverse events. Trial design, methods, and statistical analysis plan will be presented here.

DISCUSSION

We present an RCT design comparing FCA vs PRC for SLAC/SNAC-induced OA. The results of this trial will assist in decision making when planning surgery for SLAC/SNAC.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04260165 . Registered February 7, 2020.

Parallel K-Wire Placement Leads to Fusion and Midcarpal Settling in Scaphoid Excision Four-Corner Fusion

BACKGROUND

Scaphoid excision 4-corner fusion is a motion-sparing procedure in patients with advanced radioscaphoid arthritis. This study introduces an alternate technique for scaphoid excision 4-corner fusion using a parallel Kirschner wire (K-wire) construct across the midcarpal joints that leads to reliable fusion rates, and good patient outcomes.

METHODS

This is a single-surgeon, retrospective study of patients who underwent scaphoid excision 4-corner fusion, using a parallel K-wire construct across the midcarpal joints. Once fusion was achieved, K-wires were removed. Radiographic union rate, time to union, capitolunate angle, capitolunate coverage, and amount of midcarpal settling are measured. Patient-reported outcome measures and descriptive statistics are presented.

RESULTS

Sixty-five wrists were included in this study with a mean age of 50.1 years. One patient was lost to follow-up. All 64 wrists (100%) fused at an average of 2.6 months. The mean capitolunate angle was 7°, and capitolunate coverage was 99.2%. Fifty-two patients (81%) had adequate radiographs for measurement. Average midcarpal settling was 1.1 mm. Thirty-two patients (51%) were available for long-term follow-up at an average of 5.3 years (0.7-10.2 years), and participated in patient reported outcomes (PRO) surveys. The mean Quick Disabilities of the Arm, Shoulder, and Hand score was 16.6, and numeric pain rating scale score was 1.8.

CONCLUSIONS

Parallel K-wire placement across the midcarpal joints with scaphoid leads to a high rate of fusion with good patient outcomes long term. Midcarpal settling that occurs through dynamic compression around the K-wires may have contributed to bony fusion. This technique may provide an alternative approach to achieving reliable fusion across the midcarpal joints.

Surgical fixation techniques in four-corner fusion of the wrist: a systematic review of 1103 cases

BACKGROUND

Four-corner fusion (4CF) is a known treatment option for degenerative wrist conditions. Different techniques may be used and there is no general consensus on best implant. As such, it was the purpose of the current systematic review to compare fusion rates and outcomes depending on the fixation technique.

METHODS

The systematic review was registered in the international prospective register of systematic reviews (PROSPERO): CRD42020164301. It followed the PRISMA guidelines. Original articles were screened using the following databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and Web of Science Core Collection. Studies reporting on outcome for 4CF surgery were included. Studies with a minimum Level IV of evidence were considered eligible. Quality assessment was performed using the Methodological Index for Non-Randomized Studies (MINORS) criteria.

RESULTS

A total of 29 studies met the inclusion criteria, for a total of 1103 wrists. The mean age was 41.8 years (range 19-83). Mean follow-up overall was 43.5 months (range 24-146 months). Reported fusion weighted rates were >90% and did not differ significantly between techniques. Reoperations due to different reasons occurred in 135 (12%) of all 1103. There was significant data heterogeneity regarding fusion rates (I² = 70%). Inconsistency and heterogeneity in data reporting did not allow meta-analysis with direct data pooling and comparison of subgroups.

CONCLUSIONS

Satisfactory fusion rates (over 90%) can be achieved independent of the fixation technique used in 4-corner arthrodesis. Due to the high data heterogeneity and reporting inconsistency across studies, no statements regarding PROMs, ROM or grip strength can be made.

LEVEL OF EVIDENCE

Systematic Review of Level IV Studies.

Four-Corner Arthrodesis With Differing Methods of Osteosynthesis: A Systematic Review

PURPOSE

The purpose of this study was to compare the union rates and clinical outcomes of 4-corner arthrodesis with different methods of osteosynthesis.

METHODS

A systematic review of studies published in Ovid, Medline, Embase, and PubMed was conducted. Primary studies that reported clinical and radiographic results following 4-corner arthrodesis for scapholunate advanced collapse (SLAC), scaphoid nonunion advanced collapse (SNAC), or other types of wrist arthritis in human subjects were eligible. Biomechanical or cadaveric studies, case reports, studies that did not define and report a radiographic union rate, reviews and technical articles, studies that did not report the method of osteosynthesis, and studies that used multiple methods of osteosynthesis, but did not separate results for individual methods of osteosynthesis were excluded. Radiographic union rate, range of motion, and grip strength were analyzed.

RESULTS

We identified and reviewed 291 full texts, selecting 57 studies for coding. The radiographic union rate did not significantly differ between studies using K-wire, screw, staple, nonlocking plate, metal locking plate, and radiolucent locking plate osteosynthesis. Fixation method significantly affected flexion, but pairwise comparison did not reveal any significant differences between individual groups. Grip strength as a percentage of the contralateral limb was significantly lower in studies with metal locking plate fixation compared to K-wire fixation (63.2% vs 82.6%). There were no other statistically significant differences between groups with respect to flexion, extension, radial deviation, ulnar deviation, and grip strength.

CONCLUSIONS

All methods of osteosynthesis result in similar union rates, with no significant differences between methods. While there are some significant differences in range of motion and grip strength, these differences are unlikely to be clinically relevant.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Four-corner arthrodesis using the 4Fusion® quadripodal shape memory staple: a long-term review

We investigated the reliability of the 4Fusion® quadripodal memory staple in a consecutive series of 59 four-corner arthrodeses in a single centre. Forty-one patients (46 wrists) had a radiological and clinical assessment at a mean follow-up of 7.4 years. Thirteen patients (13 wrists) were lost to follow-up. Bone union was achieved in all but one patient. Seven patients were reoperated, six for device removal and one for nonunion. Most patients were satisfied, had a functional range of wrist mobility, good strength and were free of pain, comparable with the best previously reported series.Level of evidence: IV.

Long-term outcomes of the four-corner fusion of the wrist: A systematic review

BACKGROUND

Four-corner fusion (4CF) is a motion sparing salvage procedure that is used to treat osteoarthritis secondary to advanced scapholunate collapse or longstanding scaphoid nonunion advanced collapse. Little is known about the long-term survivorship and outcomes of 4CF.

AIM

To report on clinical and functional long-term outcomes as well as conversion rates to total wrist fusion or arthroplasty.

METHODS

The systematic review protocol was registered in the international prospective register of systematic reviews (PROSPERO) and followed the PRISMA guidelines. Original articles were screened using four different databases. Studies with a minimum Level IV of evidence that reported on long-term outcome after 4CF with a minimum follow-up of 5 years were included. Quality assessment was performed using the Methodological Index for Non-Randomized Studies criteria.

RESULTS

A total of 11 studies including 436 wrists with a mean follow-up of 11 ± 4 years (range: 6-18 years) was included. Quality assessment according to Methodological Index for Non-Randomized Studies criteria tool averaged 69% ± 11% (range: 50%-87%). Fusion rate could be extracted from 9/11 studies and averaged 91%. Patient-reported outcomes were extracted at last follow-up from 8 studies with an average visual analog scale of 1 ± 1 (range: 0-2) and across 9 studies with an average Disabilities of the Arm, Shoulder and Hand score of 21 ± 8 (range: 8-37). At last follow-up, the cumulative conversion rate to total wrist fusion averaged 6%. There were no conversions to total wrist arthroplasty.

CONCLUSION

The 4CF of the wrist is a reliable surgical technique, capable of achieving a good long-term patient satisfaction and survivorship with low rates of conversion to total wrist fusion.

The Effects of Different Screw Combinations on the Initial Stability of Ankle Arthrodesis

BACKGROUND

The literature is scanty regarding the biomechanical effects of different thread configurations on the initial stability of ankle arthrodesis. This study aims to compare the initial stability of tibiotalar fusion site in ankle arthrodesis using cannulated screws with different thread designs.

METHODS

We biomechanically tested under cyclic loading the effects of different screw combinations on the initial stability of ankle arthrodesis. A total of 28 synthetic ankle models were divided into four groups: two partially threaded cancellous screws (group A), partially and fully threaded cancellous screws (group B), a partially threaded cancellous screw with a headless compression screw (group C), and a fully threaded cancellous screw and a headless compression screw (group D). Biomechanical variables including ultimate failure load, initial stiffness, ultimate stiffness, and failure angulation were analyzed.

RESULTS

There were no differences in any of the biomechanical variables among the four groups (P = .41 for ultimate failure load, P = .079 for initial stiffness, P = .084 for ultimate stiffness, and P = .937 for failure angulation).

CONCLUSIONS

Combinations of different cannulated screws showed similar results in terms of the stability and stiffness of the tibiotalar fusion site.

Four-Corner Fusion with Locking Dorsal Circular Plate versus Headless Compression Screws: A Clinico-Radiological Comparative Study

Introduction Four-corner fusion is a technique for the treatment of carpal advanced collapse. It consists of scaphoid excision and arthrodesis of the lunate, triquetrum, hamate, and capitate bones. This can be accomplished with different kinds of osteosynthesis. In the first reports of the use of a circular plate, poor outcomes are described, with high rates of non-union, which decreased in later studies, which highlight certain aspects of the surgical technique.

Objective To report our experience with four-corner fusion with the use of a dorsal locking plate (Xpode, Trimed Inc., Santa Clarita, CA, US), and compare it with another traditional fixation method (3.0-mm headless compression screws [HCSs], Synthes, Slothurn, Switzerland), with an emphasis on union, an assessment of the fincitonal outcomes, and the presence of complications.

Material and Methods A comparative study of two prospective series of patients operated on through two fixation techniques for four-corner fusion using autologous bone graft from the iliac crest.

The first group of patients, evaluated between 2010 and 2012, underwent osteosynthesis with 2 HCSs, with a minimum follow up of 18 months. The second group, evaluated between 2011 and 2014, underwent osteosynthesis with a dorsal locking plate, with a minimium foloow up of 12 months. The patients were operated on by four different surgeons in four centers.

The patients were evaluated with radiographs to establish the presence of union and the time it took to occur. In case of doubt, union was confirmed through a computed tomography (CT) scan at 8 weeks postoperatrively. We also assessed the range of motion, the presence of complications, and function through the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and a grip strength score.

Results We achieved a union rate of 100% in both groups at similar times. In the dorsal locking plate group, we obtained better full range of motion, particularly in wrist extension, which was statistically significant (p = 0.0016), as well as lower DASH scores, which was also statistically significant (p = 0.0066). Complications were only present in two patients in the HCS group.

Conclusion Both techniques are valid and reproducible for the treatment of wrists with scapholunate advanced collapse (SNAC) and scaphoid non-union advanced collapse (SLAC). Based on the outcomes, with the Xpode plate, the patients presented better ranges of motion and DASH scores; therefore it may be an excellent fixation option in the open four-corner fusion surgical technique. The entry point and configuration of the HCS are fundamental variables to analyze.

The union rate of 100% obtained in the present study contrasts with the high rates of non-union reported in the literature published in the early 2000s.

Scaphoidectomy and 4-corner arthrodesis with headless compression screws: results, complications and their treatment

Scaphoidectomy and 4-corner arthrodesis is a common salvage surgery for degenerative wrist pathology. The purpose of this study was to evaluate the results of this procedure performed with headless compression screws, with a special focus on postoperative complications and their treatment. We assessed 36 wrists in 31 patients that were treated between 2009 and 2017. Mean follow-up was 5.2 years (range 2.9- 9.4). Pain was expressed on a Visual Analog Scale. The Quick Disabilities of the Arm, Shoulder and hand (qDASH) questionnaire and Michigan Hand Outcome Questionnaire (MHOQ) were used to assess patient functionality and satisfaction. Range of motion and grip strength of both wrists were measured. Radiographs of the operated wrist were evaluated. Mean pain score was 1.5 ± 2.3 with 19% of patients being completely free of pain also during activity. Mean qDASH was 44 ± 20 and mean MHOQ was 10 ± 5. Mean flexion-extension arc of the operated wrist was 69° and 61% of the contralateral wrist. Mean grip strength was 35kg and 89% of the opposite wrist. Non-union was observed in two patients. Two patients required hardware removal and in three patients a pisiformectomy was performed. Conversion to total wrist arthrodesis was needed in one patient. We observed postoperative complications in 28% of our patients. Most complications can successfully be treated with additional surgery. The presence of pisotriquetral arthritis should be assessed before surgery and treated with pisiform excision.

Four-corner fusion: Clinical and radiological outcome after fixation by headless compression screws or dorsal locking plate at minimum 5 years' follow-up

INTRODUCTION

Among the various procedures for degenerative carpal lesions, four-corner fusion relieves pain while conserving motion and strength. There are various fixation options, not presently standardised.

HYPOTHESIS

Internal fixation by screws or dorsal locking plate provides good 5-year clinical results in four-corner fusion.

MATERIAL AND METHOD

A single-centre retrospective study included 18 four-corner fusions at a minimum 5 years' follow-up: 8 plate and 10 screw fixations. Endpoints comprised pain, wrist range of motion, grip strength, QuickDASH and PRWE scores, and immobilisation time. Radiographic analysis was performed and complications inventoried.

RESULTS

Pain VAS score fell to 1/10 in both groups. Flexion-extension was 56° with screws and 55° with plates. QuickDASH was 20.5 and 4.6 respectively, and PRWE 11 and 9. Grip strength was 16kg in both groups. The consolidation rate was 85.7% with screws and 57.1% with plates. Eighty percent of patients with screw fixation progressed toward radiolunate osteoarthritis. Four patients required revision surgery: 3 in the screw group and 1 in the plate group.

DISCUSSION

There was clear clinical and functional improvement in both groups at a minimum 5 years. Consolidation was better with screw fixation, but with risk of radiolunate osteoarthritis.

LEVEL OF EVIDENCE

IV, retrospective study.

Progressing arthrosis and a high conversion rate 11 (4-19) years after four corner fusion

Four corner fusion (4CF) is a limited wrist arthrodesis offered to patients with painful wrists due to scaphoid non-union advanced collapse (SNAC) or scapho-lunate advanced collapse (SLAC). A retrospective study of 42 wrists (in 36 patients), operated with 4CF using K-wires and autologous bone graft followed up after 11 (4-19) years was performed, 25 were male and mean age at surgery was 51 (22-71) years. During the follow-up period, 13 wrists were converted to total wrist arthrodesis or wrist arthroplasty, and one is scheduled for conversion (14/42, 33%) due to non-union (3), DISI and progressing arthrosis (7) or progressing arthrosis (4). Non-union was seen in 3/42 (93%) wrists, all were later converted. At the final follow-up, the patients reported residual pain, VAS = 15 and 36 at rest and activity, respectively, and QDASH/PRWHE = 32 and 31, respectively. Active range of motion (AROM) was 38% and grip-strength was 76% compared to the uninjured side. Degenerative changes were seen in 88% on CT scans at follow-up. 4CF renders an acceptable pain reduction and function in the majority of patients, but increased degeneration and a high number of conversions after a longer follow-up time is concerning.

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.

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.

Comparative study between open and arthroscopic techniques for scaphoid excision and four-corner arthrodesis

This study presents our technique of arthroscopic scaphoid excision and four-corner arthrodesis and compares the clinical and radiological outcomes with those achieved with the open method. Twenty-seven patients (14 in arthroscopy group and 13 in open group) were included. Bone union was achieved in 13 of 14 patients in the arthroscopy group and in all 13 patients in the open group. In the open group, severe stiffness (flexion-extension arc was 10°) occurred in one patient after surgery. The mean postoperative flexion-extension arc was 75° and 51° in the arthroscopy group and open group, respectively. The pain, clinical scores, and radiological indices were improved in both arthroscopy and open groups. Arthroscopic and open scaphoid excision and four-corner arthrodesis did not show significant differences in clinical outcomes and bone union rates. The arthroscopic method provided a superior range of motion.Level of evidence: III.

Four-corner fusion method using a bioabsorbable plate for scapholunate advanced collapse and scaphoid nonunion advanced collapse wrists: a case series study

Background

Scaphoid excision and four-corner arthrodesis is an acceptable salvage procedure for the treatment of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrists, since first popularized in the 1980s. We investigated the potential application of novel bioabsorbable plates and screws made of un-sintered hydroxyapatite/poly-L-lactide composite for the treatment of metacarpal fractures. We used this material for the fixation of four-corner fusions for SLAC or SNAC wrists commencing from April 2009. The purpose of this study was to clarify the controversy in the literature regarding the use of these plates.

Methods

The surgical procedures and clinical outcomes of four-corner fusions using a bioabsorbable (poly-L-lactic acid and hydroxyapatite) plate were reported. Ten patients (mean age, 59.2 years) with SLAC or SNAC wrists underwent fusions between April 2009 and June 2016. The primary diseases were scapholunate ligament injury, Preiser disease, and scaphoid pseudarthrosis. The mean postoperative follow-up period was 45.9 months (range, 12–86).

Results

In all patients, bone union was achieved without dislocation or pain. The mean wrist flexion and extension arc improved from 78.5 degrees before surgery to 90.5 degrees after surgery. Mean grip strength improved from 51 to 69% after surgery, and the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score improved from 53.5 to 14.3. No complications such as infection, avascular swelling, or tendon adhesion were observed. This implant requires no removal of internal fixation devices, produces stable outcomes, and is an effective fusion technique.

Conclusions

We summarized the outcomes of four-corner arthrodesis using bioabsorbable plates. Satisfactory clinical results were shown, with no obvious complications. This novel plate also serves as a good alternative for patients who are allergic to metals. Furthermore, bioabsorbable plates are advantageous as they do not require removal.

Proximal Row Carpectomy Versus 4-Corner Fusion: Incidence, Conversion to Fusion, and Cost

PURPOSE

The primary objective of this study was to compare incidence, demographic trends, and rates of subsequent fusion between proximal row carpectomy (PRC) and 4-corner fusion (4CF) among patients in the United States.

METHODS

A total of 3,636 patients who underwent PRC and 5,047 who underwent 4CF were identified from the years 2005 through 2014 among enrollees in the PearlDiver database. Regional distribution, demographic characteristics, annual incidence, comorbidities, and subsequent wrist fusion were compared between the 2 groups. Of the patients identified, 3,512 from each group were age- and sex-matched and subsequently compared for rates of converted fusion, 30- and 90-day readmission rates, and average direct cost.

RESULTS

Patients undergoing 4CF and PRC did not have statistically significant differences in comorbidities. The incidence of the procedures among all subscribers increased for both PRC (1.8 per 10,000 to 2.6 per 10,000) and 4CF (1.2 per 10,000 to 2.0 per 10,000) from 2005 to 2014. Comparing the matched cohorts, patients who underwent 4CF had a higher rate of subsequent fusion than those who underwent PRC (2.67% vs 1.79%). Readmission rates were not significantly different at 30 or 90 days. Average direct cost was significantly greater for 4CF than for PRC.

CONCLUSIONS

Both PRC and 4CF have been utilized at increasing rates in the past decade. Wrist fusion rates and average costs are higher in the 4CF group without a significant difference in readmission rates.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

Dorsal Intercarpal Ligament Preserving Arthrotomy and Capsulodesis for Scapholunate Dissociation

Carpal instability secondary to scapholunate (SL) ligament tears can lead to a significant disability of the wrist. Different surgical procedures have been proposed to treat SL instability. A variety of dorsal capsulodesis techniques tethering the scaphoid have been used in patients with SL dissociation. We report a novel technique of modified dorsal intercarpal ligament (DICL) capsulodesis for the treatment of SL dissociation. The surgical indication for this procedure is complete SL ligament tear with a reducible carpal malalignment and no secondary osteoarthritis. This procedure is indicated when the remnant of torn ligament in the dorsal SL interosseous space is available for repair. First, carpal malalignment is corrected and the scaphoid and the lunate are temporarily fixed with a transosseous screw or Kirschner wires. Using a dorsal approach, the DICL is then exposed, which originates from the triquetrum and attaches to the scaphoid, trapezium, and trapezoid. The distal and proximal borders of the ligament are identified and elevated without detaching the attachment sites. The DICL is transferred proximally to reinforce the dorsal SL interosseous ligament. The wrist joint is immobilized for 3 weeks postoperatively, and dart-throwing motion is permitted until temporary SL fixation is removed at 2 to 3 months after surgery. A wrist brace is recommended until 3 to 6 months after the first surgery depending on the patient's occupation and sports activity.

Clinical and radiological outcomes of 40 cases of SLAC and SNAC wrist treated by four-corner arthrodesis with locking plate

The treatment of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist varies. No clear consensus exists on surgical indications. Scaphoid excision and four-corner arthrodesis with locking plate is one of preferred treatments for these lesions. The purpose of this study was to assess the clinical and radiological outcomes of locking plates for treating SNAC and SLAC wrist after a mean follow-up of 5 years and to compare these outcomes with the results reported in the literature. A retrospective study was conducted in two hospitals, involving 40 patients who underwent scaphoid excision and four-corner arthrodesis with locking plate between January 2006 and September 2016. All patients were reviewed as outpatients with clinical and radiographic measurements. At the last follow-up, the mean pain level on visual analog scale (VAS) was 2.5/10 [0-7] (SD: 1.7). Patients had a mean flexion of 46% and a mean extension of 46% compared to the contralateral side. An 18% gain was observed in grip strength. The mean postoperative QuickDASH score was 30 [0-57] (SD: 15.3). Seventy percent of patients were satisfied with the operation. Complete (all four joint interfaces) joint space fusion was achieved in 55% of patients. Only one patient (2.5%) had no joint fusion. The joint between the lunate and the capitate was fused in 38 patients (95%). Nine patients suffered complications; eight of them required surgical revision (20%). Four-corner arthrodesis with locking plate is a valuable surgical technique for treating SLAC and SNAC wrist because it preserve satisfactory range of motion and grip strength (64% compared to the non-operated side), maintains the height of the carpus and prevents the premature appearance of radiocarpal osteoarthritis, as long as the technical challenges of this procedure are mastered.

The Learning Curve and Pitfalls of Arthroscopic Four-Corner Arthrodesis

Background  Midcarpal "four-corner" wrist arthrodesis may be done from an open arthrotomy or arthroscopically. Purpose  This study aimed to examine the results of the recently described arthroscopic four-corner arthrodesis and whether the procedure seems to have any merit compared with the open technique. Patients and Methods  We retrospectively identified eight patients with nine cases of arthroscopic four-corner arthrodesis performed at our institution, 2014 to 2017. The underlying pathologies were scapholunate advanced collapse ( n  = 6), Preiser's disease ( n  = 1), radioscaphoid ( n  = 1), or capitolunar ( n  = 1) osteoarthritis. Osteosynthesis was done with cannulated compression screws. Results  Operating time for the first surgery was 198 minutes while the final one lasted 132 minutes. All patients achieved fusion. Three patients required a reoperation; one for screw malposition with screw removal, one for tendon reconstruction and screw removal due to a tendon injury induced by a retracted screw, and one for scaphoid impingement with removal of the scaphoid remnants. One patient experienced a probable superficial radial nerve injury. The follow-up time was 5 to 16 months. Conclusion  The arthroscopic approach is technically extremely demanding and has a learning curve. Thorough resection of the scaphoid is recommended to avoid potential impingement. Level of Evidence  This is a level IV, retrospective case series.

Proximal Row Carpectomy versus Four-Corner Arthrodesis for the Treatment of Scapholunate Advanced Collapse/Scaphoid Nonunion Advanced Collapse Wrist: A Cost-Utility Analysis

BACKGROUND

Two mainstay surgical options for salvage in scapholunate advanced collapse and scaphoid nonunion advanced collapse are proximal row carpectomy and four-corner arthrodesis. This study evaluates the cost-utility of proximal row carpectomy versus three methods of four-corner arthrodesis for the treatment of scapholunate advanced collapse/scaphoid nonunion advanced collapse wrist.

METHODS

A cost-utility analysis was performed in accordance with the Second Panel on Cost-Effectiveness in Health and Medicine. A comprehensive literature review was performed to obtain the probability of potential complications. Costs were derived using both societal and health care sector perspectives. A visual analogue scale survey of expert hand surgeons estimated utilities. Overall cost, probabilities, and quality-adjusted life-years were used to complete a decision tree analysis. Both deterministic and probabilistic sensitivity analyses were performed.

RESULTS

Forty studies yielding 1730 scapholunate advanced collapse/scaphoid nonunion advanced collapse wrists were identified. Decision tree analysis determined that both four-corner arthrodesis with screw fixation and proximal row carpectomy were cost-effective options, but four-corner arthrodesis with screw was the optimal treatment strategy. Four-corner arthrodesis with Kirschner-wire fixation and four-corner arthrodesis with plate fixation were dominated (inferior) strategies and therefore not cost-effective. One-way sensitivity analysis demonstrated that when the quality-adjusted life-years for a successful four-corner arthrodesis with screw fixation are lower than 26.36, proximal row carpectomy becomes the optimal strategy. However, multivariate probabilistic sensitivity analysis confirmed the results of our model.

CONCLUSIONS

Four-corner arthrodesis with screw fixation and proximal row carpectomy are both cost-effective treatment options for scapholunate advanced collapse/scaphoid nonunion advanced collapse wrist because of their lower complication profile and high efficacy, with four-corner arthrodesis with screw as the most cost-effective treatment. Four-corner arthrodesis with plate and Kirschner-wire fixation should be avoided from a cost-effectiveness standpoint.

Limited Wrist Arthrodesis for Scapholunate Advanced Collapse Wrist: Triangle Fixation for Four-Corner Fusion

BACKGROUND

Limited wrist arthrodesis with scaphoid excision is a useful treatment for scapholunate advanced collapse (SLAC) of the wrist. Multiple Kirschner wires were originally used for internal fixation of the four carpal bones, however long-term cast immobilization, pin tract infection, and hardware removal are still problematic. We introduce and evaluate the clinical outcomes of an internal fixation technique; triangle fixation for four-corner fusion, using three headless screws, as an alternative to conventional multiple Kirschner wires for the treatment of SLAC wrist.

METHODS

Five male patients with SLAC wrist secondary to three scaphoid nonunions and two scapholunate dissociations were treated with four-corner fusion using triangle fixation with three Double-threaded Japan screws. The mean age was 59.5 years (35-79 years) and the mean follow-up period was 40 months. After surgery, short arm splints were applied for 3-4 weeks, and then range of motion exercises were initiated.

RESULTS

Wrist range of motion and grip strength both improved postoperatively. At the final follow-up evaluation, bone union was completely achieved and satisfactory pain relief was observed in all patients.

CONCLUSIONS

Compared with the conventional Kirschner wire technique, the present technique shortens the period of splint immobilization due to a strong compression force in a skewed position, does not require pin removal or cause pin tract infections, and provides satisfactory results.

Proximal row carpectomy, scaphoidectomy with midcarpal arthrodesis or midcarpal tenodesis: when and how to use

I report my personal experience over three decades in the treatment of carpal collapse due to scapholunate collapse and scaphoid nonunion. I have used the proximal carpal row resection performed through palmar approach, the scaphoidectomy and double-column midcarpal arthrodesis, and scaphoidectomy with midcarpal tenodesis. Diagnostic arthroscopy is essential for staging and surgical decision making regarding the type of treatment. The details of the surgical techniques, tips, results and possible complications are described for each method. The advantage of the proximal row carpectomy by palmar approach is the early permitted rehabilitation with better recovery of wrist motility in comparison with the traditional technique. The advantage of the double-column midcarpal arthrodesis lies in its ease of execution. The midcarpal tenodesis is an excellent intervention from the conceptual point of view even if over time there is a progressive carpal collapse even in absence of symptoms.

Treatment Outcomes of 4-Corner Arthrodesis for Patients With Advanced Carpal Collapse: An Average of 4 Years' Follow-Up Comparing 2 Different Plate Types

PURPOSE

The objective was to investigate the clinical and subjective outcomes of patients after 4-corner arthrodesis (FCA) for scapholunate advanced collapse (SLAC) or scaphoid nonunion advanced collapse (SNAC) and to analyze complications. Furthermore, we compared the long-term results of a first-generation nonlocking plate (Spider) and a plate with a locking screw design (Flower plate).

METHODS

In a retrospective cohort study, we included 39 patients with stage II or III SLAC or SNAC who underwent FCA. Twenty wrists were treated with a nonlocking plate and 19 with a locking plate. Patients completed the Patient-Rated Wrist Evaluation (PRWE) and the Michigan Hand Outcomes Questionnaire (MHQ). Active range of wrist motion, radiological signs such as impingement, and signs of implant loosening and nonunion, as well as postoperative complications, were assessed.

RESULTS

After a median postoperative follow-up time of 4.1 years, the PRWE score was 18 and the total MHQ score 79. Patient-reported and clinical outcomes were similar for the 2 plate types. Wrists fixed with the nonlocking plate had more dorsal impingements and loosening than wrists fixed with a locking plate. One nonunion was noted in the nonlocking plate group, and a single case of implant failure was seen for each plate type. A total of 5 patients with a nonlocking plate incurred postoperative complications that required further medical treatment.

CONCLUSIONS

FCA for patients with stage II or III SLAC or SNAC yields positive clinical and subjective outcomes. Based on the high complication rate following FCA with a nonlocking plate, we no longer use this implant and recommend fixation with a locking screw plate.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Four-Corner Arthrodesis: Description of Surgical Technique Using Headless Retrograde Crossed Screws

BACKGROUND

Four-corner fusion has been shown to be a reliable option of treatment of wrist arthritis, but there is no consensus about which implant and surgical procedure should be used in the arthrodesis. The present study aimed to describe a surgical technique using 2 crossed screws as implants, inserted in a retrograde manner, and to demonstrate preliminary results of the use of the technique.

METHODS

A retrospective study was conducted using medical records and imaging tests (radiographs and computed tomography) of all 15 patients who underwent a standardized 4-corner fusion technique, between December 2011 and July 2015, in the Department of Hand Surgery of Instituto Nacional de Traumatologia e Ortopedia (INTO), Rio de Janeiro, Brazil. We collected data on the following variables: fusion rate, time to fusion, and percentage of patients who had any complications or needed another surgical procedure on the same wrist.

RESULTS

All but one patient achieved fusion of arthrodesis. The average time to union was 5.54 months (SD = 3.84). Only the patient who developed nonunion of the 4-corner fusion required another surgery on the same wrist.

CONCLUSIONS

The procedure described in this study demonstrated a low complication rate and high fusion rate, and can therefore be considered a reliable surgical technique for 4-corner fusion.

Ten-Year Minimum Follow-Up of 4-Corner Fusion for SLAC and SNAC Wrist

BACKGROUND

Scapholunate advanced collapse (SLAC) of the wrist is the most common degenerative condition of the wrist. Four-corner fusion (4CF) is performed as salvage surgery, though there is limited information on its long-term results. We hypothesized that 4CF is a durable surgery with good clinical long-term function.

METHODS

A retrospective chart review of patients undergoing 4CF as well as an interview and recent radiographs were obtained. Patients with a follow-up period of less than 10 years were excluded. Long-term evaluation included standard wrist radiographs, wrist range of motion, and the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire. Radiographs were evaluated and described by the Kellgren-Lawrence classification.

RESULTS

Four hundred eighty-nine wrists underwent a 4CF for SLAC wrist from 1982 to 2003. Twelve patients (15 wrists) were available for follow-up. Average age at surgery was 49.1 years (range, 25-67 years). Average follow-up postsurgery was 18 years (11-27). Scapholunate advanced collapse was the etiology in 13 wrists and scaphoid nonunion advanced collapse in 2 wrists. Average extension/flexion arc was 68.6° (0°-96°), and radial/ulnar deviation arc was 32.9° (0°-5°). QuickDASH scores averaged 7.8 (range, 0-32.5), with only 1 score above 16. Seventy-three percent of radiographs showed minimal to moderate joint destruction, and 27% showed severe joint destruction.

CONCLUSIONS

Scaphoid excision and 4CF remains a reliable procedure for patients with advanced wrist arthritis. Functional results were good at long-term follow-up despite radiographic changes in the radiolunate joint in 73% of patients. Patient satisfaction was high, and functional impairment was low.

Arthroscopic-Assisted Partial Wrist Arthrodesis

Partial wrist arthrodesis (PWA) is a well-known procedure for treating degenerative or posttraumatic wrist conditions. Four-corner fusion (4CF) is mostly used for scapholunate advanced collapse and scaphoid nonunion advanced collapse. The author performed 39 procedures, including 4CFs, 2-corner fusions, 3-corner fusions, scaphoid-capitate/scaphoid-capitate-lunate fusions, scaphoid-trapezium-trapezoid arthrodeses, and radioscapholunate arthroscopic PWAs (A-PWAs). There were 8 revision cases including 4 partial nonunions. All A-PWAs healed satisfactorily after revision surgery. This article discusses the surgical techniques and tips to avoid mistakes. The pros and cons for open versus arthroscopic techniques and for screws versus Kirschner wires are also discussed.

Four-corner arthrodesis employing the native scaphoid as the principal donor graft for advanced collapse deformity of the wrist: technique and outcomes

The purpose of this study was to determine the functional, radiographic, and subjective outcome of the authors' technique of four-corner arthrodesis using the en bloc excised scaphoid as the principal donor bone graft coupled with Kirschner wire fixation. The study comprised 40 consecutive patients with progressive Stage II and III scapholunate advanced collapse or scaphoid nonunion advanced collapse deformities. Preoperative and postoperative range of motion, grip strength, carpal height, and Michigan Hand Outcomes Questionnaire responses were assessed with a mean follow-up of 4.4 years. At an average of 7 weeks, all patients demonstrated radiographic fusion. Moreover, postoperatively, improvement in the Michigan Hand Outcomes Questionnaire domains of overall function, activities of daily living, work performance, pain, and satisfaction were statistically significant. Complications were few and no patient required revision surgery. In this study, the authors' technique results in a reliable four-corner arthrodesis with a low expectation of complications or revision surgery.

LEVEL OF EVIDENCE

IV.

The Effect of Capitate Position on Coronal Plane Wrist Motion After Simulated 4-Corner Arthrodesis

PURPOSE

The objective of this study was to examine the effect of altering the capitolunate relationship on coronal-plane wrist motion after scaphoidectomy and simulated 4-corner arthrodesis. Two positions of different capitolunate alignments were compared: "anatomic" (unchanged from pre-fusion) and "lunate-covered" (capitate translated to cover the lunate). We hypothesized that wrist resting posture would be altered and radial-ulnar motion would diminish after 4-corner arthrodesis in the lunate-covered position when compared with normal wrists.

METHODS

Six human cadaveric limbs were disarticulated at the elbow and mounted on a custom jig. The resting position of the wrist was recorded with no load applied, followed by a load of 44 N applied to the flexor carpi radialis, extensor carpi radialis longus, and extensor carpi radialis brevis tendons to simulate radial deviation and to the flexor carpi ulnaris and extensor carpi ulnaris tendons to simulate ulnar deviation. Scaphoidectomy was performed and 2 methods of 4-corner arthrodesis with different capitolunate coronal alignments were studied in random order. Range of motion was compared using one-way analysis of variance and Bonferroni correction.

RESULTS

The "lunate covered" wrist demonstrated significantly greater radial resting posture than that of the preoperative wrist. Under a 44 N load, the lunate-covered position had significantly greater radial motion than the preoperative radial motion. Wrists fused in the "anatomic" position did not differ significantly from the preoperative wrists in posture or range of motion.

CONCLUSIONS

In this cadaveric model, complete covering of the capitate head by the lunate placed the wrist in increased radial deviation compared with the anatomic posture. Changes induced in the resting tension of the extrinsic wrist ligaments serve as a reasonable explanation for the increased radial posture and motion. In a clinical setting, these changes may affect postoperative wrist posture and function.

CLINICAL RELEVANCE

Maintaining anatomic lunate position leads to preservation of greater wrist motion and anatomic alignment in a patient undergoing 4-corner arthrodesis.

An Unusual and Complicated Course of a Giant Cell Tumor of the Capitate Bone

A 51-year-old female patient presented with a carpal giant cell tumor (GCT) of the right capitate bone. The lesion was initially misdiagnosed as having an osteomyelitis. First, the diagnosis of a benign GCT was confirmed by histological examination. Second, an intralesional curettage and packing of the cavity with cancellous iliac crest bone grafts combined with a fusion of the third carpometacarpal (CMC III) joint were carried out. Third, due to a secondary midcarpal osteoarthritis and a secondary scaphoid nonunion, the CMC III joint fusion plate was removed and the midcarpal joint completely excised. Fourth, in the absence of recurrence of GCT, a four-corner fusion (4CF) with a corticocancellous iliac crest bone graft and complete excision of the scaphoid bone had to be performed. Fifth, a total wrist arthroplasty (TWA) was performed due to hardware failure of 4CF with migration of a headless compression screw into radiocarpal joint which led to erosion of articular surface of the distal radius. At the 3-year follow-up that includes a 1-year follow-up after TWA, there was no recurrence of GCT, and the TWA was not failed. The patient reported that she would have the motion-preserving TWA again.

Four-corner fusion of the wrist: clinical and radiographic outcome of 31 patients

BACKGROUND

Four-corner fusion is a rational surgical option for the management of degenerative conditions of the wrist. Most related studies have compared four-corner fusion with scaphoid excision or proximal row carpectomy, with a variety of reported results. To enhance the literature, we performed this study to evaluate a series of patients with degenerative conditions of the wrist treated with four-corner fusion using 3 surgical techniques and to discuss the clinical and radiographic outcome of the patients.

MATERIALS AND METHODS

We retrospectively studied 31 patients (24 men, 7 women; mean age, 43 years; 9 heavy manual laborers) who underwent four-corner fusion of their wrists for degenerative conditions from 2005 to 2015. Internal fixation was done using multiple Kirschner wires (14 patients), headless compressive screws (8 patients), or a circular plate (9 patients). Mean follow-up was 4 years (1-11 years). We evaluated the clinical outcome with the Patient-Rated Wrist Evaluation (PRWE) score and fusion with radiographs.

RESULTS

All patients experienced improvement of their pain, function, range of motion and grip strength (p < 0.05). Twenty-three patients (74 %) reported no pain, and eight patients reported mild, occasional pain. Twenty-one patients (68 %) were able to do usual and specific activities. Mean wrist motion improved to 70 % and mean grip strength improved to 85 % of opposite wrist. Two heavy manual labor patients requested a job modification because of wrist impairment. Radiographs of the wrist showed fusion of all fused joints in 28 (90.3 %) patients and partial fusion in three patients (9.7 %). No patient with partial fusion required a reoperation for symptomatic nonunion until the period of this study. Three patients experienced complications (10 %). Two patients treated with a circular plate experienced complex regional pain syndrome and painful implant impingement; another patient treated with Kirschner wires and headless compression screws experienced radiolunate arthritis from impingement of the lunate screw to the radius.

CONCLUSIONS

Four-corner fusion is a reliable limited wrist fusion technique that provides pain relief, grip strength and satisfactory range of motion in patients with degenerative conditions of the wrist. Partial union is more common with Kirschner wire fixation and complications are more common with circular plate fixation.

Biomechanical evaluation of a second generation headless compression screw for ankle arthrodesis in a cadaver model

BACKGROUND

Many types of screws, plates, and strut grafts have been utilized for ankle arthrodesis. Biomechanical testing has shown that these constructs can have variable stiffness. More recently, headless compression screws have emerged as an evolving method of achieving compression in various applications but there is limited literature regarding ankle arthrodesis. The aim of this study was to determine the biomechanical stability provided by a second generation fully threaded headless compression screw compared to a standard headed, partially threaded cancellous screw in a cadaveric ankle arthrodesis model.

MATERIALS AND METHODS

Twenty fresh frozen human cadaver specimens were subjected to simulated ankle arthrodesis with either three standard cancellous-bone screws (InFix 7.3mm) or with three headless compression screws (Acumed Acutrak 2 7.5mm). The specimens were subjected to cyclic loading and unloading at a rate of 1Hz, compression of 525 Newtons (N) and distraction of 20N for a total of 500 cycles using an electromechanical load frame (Instron). The amount of maximum distraction was recorded as well as the amount of motion that occurred through 1, 10, 50, 100, and 500 cycles.

RESULTS

No significant difference (p=0.412) was seen in the amount of distraction that occurred across the fusion site for either screw. The average maximum distraction after 500 cycles was 201.9μm for the Acutrak 2 screw and 235.4μm for the InFix screw. No difference was seen throughout each cycle over time for the Acutrak 2 screw (p-value=0.988) or the InFix screw (p-value=0.991).

CONCLUSION

Both the traditional InFix type screw and the second generation Acumed Acutrak headless compression screws provide adequate fixation during ankle arthrodesis under submaximal loads.

CLINICAL RELEVANCE

There is no demonstrable difference between traditional cannulated partially threaded screws and headless compression screws studied in this model.

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.

Relationship Between Wrist Motion and Capitolunate Reduction in Four-Corner Arthrodesis

The authors retrospectively studied 36 patients with degenerative changes associated with scaphoid nonunion and scapholunate advanced collapse treated with circular plate fixation and bone graft. The goals of the study were to review the incidence of dorsal impingement, nonunion of arthrodesis, loose hardware, broken screws, and limitation in wrist motion associated with correct or incorrect surgical capitolunate reduction. Surgical indications were scapholunate advanced collapse (3 patients), scaphoid nonunion advanced collapse (32 patients), and sequelae of irreducible perilunate dislocation (1 patient). All of the patients were men, with a mean age of 48 years (range, 35-68 years). Average follow-up was 56 months (range, 12-108 months). Functional outcomes evaluated were pain with the visual analog scale, range of motion, grip strength, Disabilities of the Arm, Shoulder and Hand (DASH) score, satisfaction, and time to union. Mean visual analog scale score was 7 (range, 5-9) preoperatively and 1 (range, 0-2) postoperatively. Average wrist range of motion was 42° in extension, 36° in flexion, 15° in ulnar deviation, and 12° in radial deviation. Mean grip strength was 34 kg preoperatively, 50 kg postoperatively, and 56 kg contralaterally. Thirty-five of the 36 patients achieved union at 6 months. Degenerative changes at the radiolunate articulation were present in 1 patient 62 months after surgery, but he was asymptomatic. Mean capitolunate angle was 38º preoperatively and 9º postoperatively. Poor correlation was found between the measured capitate-lunate angle and subsequent flexion and extension (r=0.32 and r=0.17, respectively) using the Pearson correlation coefficient. The authors noted 1 or 2 broken screws in 3 cases (8.3%) and hardware dorsal impingement in the plate in 6 cases (16.6%). Mean DASH score was 24 of 100. Overall patient satisfaction was 70%.

Clinical outcomes of proximal row carpectomy versus four-corner arthrodesis for post-traumatic wrist arthropathy: a systematic review

We conducted a systematic review of studies reporting clinical outcomes after proximal row carpectomy or to four-corner arthrodesis for scaphoid non-union advanced collapse or scapholunate advanced collapse arthritis. Seven studies (Levels I-III; 240 patients, 242 wrists) were evaluated. Significantly different post-operative values were as follows for four-corner arthrodesis versus proximal row carpectomy groups: wrist extension, 39 (SD 11º) versus 43 (SD 11º); wrist flexion, 32 (SD 10º) versus 36 (SD 11º); flexion-extension arc, 62 (SD 14º) versus 75 (SD 10º); radial deviation, 14 (SD 5º) versus 10 (SD 5º); hand grip strength as a percentage of contralateral side, 74% (SD 13) versus 67% (SD 16); overall complication rate, 29% versus 14%. The most common post-operative complications were non-union (grouped incidence, 7%) after four-corner arthrodesis and synovitis and clinically significant oedema (3.1%) after proximal row carpectomy. Radial deviation and post-operative hand grip strength (as a percentage of the contralateral side) were significantly better after four-corner arthrodesis. Four-corner arthrodesis gave significantly greater post-operative radial deviation and grip strength as a percentage of the opposite side. Wrist flexion, extension, and the flexion-extension arc were better after proximal row carpectomy, which also had a lower overall complication rate.

The long-term outcome of four-corner fusion

Introduction Four-corner arthrodesis with excision of the scaphoid is an accepted salvage procedure for scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) and has been performed in our unit for over 20 years. We have undertaken a retrospective review of 116 of these procedures performed in 110 patients between 1992 and 2009. Fifty-eight patients attended for a clinical evaluation, and 29 responded by postal questionnaire. Methods The surgical technique undertaken was standard. That is, through a dorsal approach the scaphoid and tip of the radial styloid were excised. The capitate, lunate, triquetrum, and hamate articular surfaces were then prepared down to bleeding bone. Bone grafts from the scaphoid and radial styloid were then inserted and fixation undertaken. For the latter, various methods were used, including Kirschner (K-)wires, staples, bone screws, but predominantly the Spider plate (Integra Life Sciences, USA). Thereafter the wrist was immobilized for a minimum period of 2 weeks prior to rehabilitation. Results Follow-up was done at a mean of 9 years and 4 months (range 3-19 years). All patients reported a significant improvement in pain relief and ∼50% of flexion extension, although only 40% of radioulnar deviation. Grip strength was again ∼50% of the contralateral side. Most patients reported a significant improvement in function with 87% returning to work. In addition, radiologic evaluation identified 28 patients (31%) who demonstrated ongoing signs of nonunion, particularly around the triquetrum. Fourteen of these (15%) underwent a further procedure, generally with success. Finally, none of the patients demonstrated any arthritic changes in the lunate fossa on follow-up X-ray, and all secondary procedures were undertaken within 2 years of the primary. Discussion This research has demonstrated that four-corner fusion fixed with a circular plate can result in a satisfactory outcome with a reduction in pain, a functional range of motion, and a satisfactory functional outcome. The bulk of the complications appear to occur in the first 2 years after surgery. Thereafter, analysis shows long-term satisfaction with little deterioration. Nonunion, particularly around the triquetrum, continues to be a problem, but it may be that this bone should be excised along with the scaphoid, resulting in a three-part fusion only. Alternatively, a simple capitolunate fusion may be satisfactory.

Proximal migration of hardware in patients undergoing midcarpal fusion with headless compression screws

Background Scaphoid excision and limited intercarpal fusion is a common surgical procedure performed for degenerative disorders of the wrist including scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist deformities. Postoperative screw migration is a rare but devastating complication that can result in severe degenerative changes in the radiocarpal joint. Questions/Purposes The purpose of this study is to report on a series of patients who developed proximal migration of their hardware following limited intercarpal fusions with headless compression screws. Patients and Methods Four patients were identified between 2001 and 2012 who were indicated for and underwent scaphoid excision and midcarpal fusions with headless compression screw fixation and subsequently developed hardware migration with screw protrusion into the radiocarpal joint. Detailed chart review was performed. Results Mean age at surgery was 64 years (57-69 years). All patients had the diagnosis of SLAC wrist. Mean time to detection of failure was 6 months (4-8 months). All patients demonstrated radiographic union prior to failure based on plain films. Radiographs revealed screw backout with erosion of the radial lunate facet in all patients. Calculated carpal height ratios demonstrated a drop from an average 44.2% to 39.5% at the time of hardware migration. All four patients underwent hardware removal. One patient was not indicated for any further surgery, and two patients underwent further revision surgery. All three patients reported complete pain relief. One patient refused a salvage procedure and had subsequent persistent pain. Conclusions This study reports a serious complication of scaphoid excision and midcarpal fusion performed with headless compression screws. We advise surgeons to be aware of this potential complication and consider employing methods to reduce the risk of hardware migration. Additionally, we recommend at least 8 months of clinical and radiographic follow-up postoperatively to enable early intervention if necessary. Level of Evidence Level IV, therapeutic study.

Dorsal locking plates versus staples in four-corner fusion: a comparative clinical and radiological study

INTRODUCTION

Four-corner fusion was described in 1984 by HK Watson for the treatment of SLAC wrist. This intervention has undergone few changes since that description, but the debate on the fixation method is still not resolved.

HYPOTHESIS

Dorsal locking plates provide better stability, short immobilization and a quicker return to daily activities than traditional fixation methods such as staples.

MATERIALS AND METHODS

Thirty-one fusions using the Medartis Aptus Four-Corner Fusion(®) plate at a mean 13.1 months' follow-up and 35 using staples at a mean 80.4 months' follow-up were reviewed in a clinical and radiographic retrospective comparative study.

RESULTS

Results were comparable between the two groups in terms of range of motion (flexion-extension arc of 67.3° for plates and 60.6° for staples), force (29.6 and 28 kg.F), pain and disability (PRWE 34.8/150 and 40.9; QuickDASH 19.83/100 and 30). Mean time off work was significantly shorter in the plate group (4.5 vs. 7.9 months). There were no non-unions in the plate group, versus 2 in the staples group. Dorsal impingement implicating hardware was also less frequent in the plate group (2 vs. 11).

DISCUSSION

The dorsal locking plate did not improve final results in four-corner fusion in terms of range of motion, force, pain or function compared to staples. However, it provided stable fixation, allowing a shorter immobilization and a quicker return to work. Although the initial cost is higher, it could allow significant savings on postoperative costs, shifting the technical debate into the field of public health.

LEVEL OF EVIDENCE

Level IV, retrospective study.

Osteoarthritis of the wrist

This article reviews pathogenesis and treatment of wrist osteoarthritis. Because there is no cure for osteoarthritis, treatment is directed at symptomatic relief. Surgical treatment is reserved for patients who have failed nonoperative modalities. This article reviews the surgical treatment of wrist osteoarthritis with an emphasis on selection of the appropriate procedure. Literature guiding surgical treatment with patient outcomes is reviewed.

Early motion following 4-corner arthrodesis using cannulated compression screws: a biomechanical study

PURPOSE

To assess the ability of headless compression screws to maintain immobile bony contact throughout wrist cycling following simulated 4-corner arthrodesis. Our hypothesis was that the screw constructs would not permit displacement of the carpal bones and, therefore, could tolerate early postoperative range of motion in vivo.

METHODS

Using 6 matched-paired cadaveric arms, 4-corner arthrodesis was performed using an all-cannulated compression screw construct (capitolunate, lunotriquetral, and triquetrohamate screws) or a partial compression screw combined with partial K-wire construct (2 crossing capitolunate screws with the lunotriquetral and triquetrohamate interfaces immobilized with 2 K-wires). Wrists were mounted and cycled 5,000 times. Intercarpal distances were measured at 0, 100, 1,000, and 5,000 cycles at fixed points of passive flexion. Because previously published studies considered intercarpal distances of greater than 1 mm as significant, we defined fixation failure as greater than 0.5 mm gapping.

RESULTS

Neither screw construct showed any significant intercarpal gapping at any point during the experimental cycling (largest average intercarpal gapping was 0.2 mm). There were no significant differences between the constructs regarding gapping at any point.

CONCLUSIONS

In this biomechanical model, cannulated compression screws effectively resist significant intercarpal gapping during early motion after 4-corner arthrodesis. This may allow for immediate postoperative range of motion.

CLINICAL RELEVANCE

Early gentle range of motion may be possible immediately following 4-corner arthrodesis using a construct consisting of headless compression screws.

[Capitolunate arthrodesis: 12 patients followed-up an average of 10 years]

The aim of the study was to evaluate long-term results of capitolunate arthrodesis for the treatment of posttraumatic degenerative wrist disorders. A capitolunate arthrodesis was performed on 12 patients, three women and nine men, of 45 years on average (28-66). Ten patients were manual workers. Dominant side was involved in seven cases. Indications were nine scapholunate dissociations (SLAC) and three scaphoid non-unions (SNAC) with degenerative lesions. Fixation of the arthrodesis was performed with K-wires in seven, K-wires and staples in two, and only staples in three. Patients were reviewed at 118 months of average follow-up (72-168). One complete wrist arthrodesis was necessary one year after the capitolunate arthrodesis for an evolutive painful osteoarthritis. For the 11 remaining patients, pain on visual analogic scale (VAS) was 0.5. The flexion/extension arc was decreased of 25° and strength of 6kg compared to preoperative values. DASH score was equal to 33.7 points, Cooney score to 77.2 points and Mayo score to 82.8 points. Radiolunate and capitolunate angles were decreased of 4.9° and 6.2° respectively compared to preoperative values. Some complications occurred: evolutive osteoarthritis between triquetrum and lunate in two, non-union of the arthrodesis in one, and reflex sympathetic dystrophy in two. Nine patients were able to return to their previous professional activities. Capitolunate arthrodesis allowed restoring a pain free and functional wrist in eight out of the 11 patients reviewed. Results were maintained with follow-up. It is a satisfactory therapeutic alternative to four corners fusion for chronic instability of the wrist with osteoarthritis.

LEVEL OF EVIDENCE

IV.

Radioscapholunate arthrodesis with compression screws and local autograft

Radioscapholunate arthrodesis is performed for patients who experience pain and disability from radiocarpal arthritis. Initial reports from the 1980s demonstrated high nonunion rates and marginal clinical outcomes. Improvements in surgical technique and clearly defined indications have reduced nonunion rates and improved patient satisfaction. We present a technique using headless compression screws inserted through a dorsal approach, which optimizes hardware placement and incorporates local bone graft harvested from the insertion site to supplement the arthrodesis.

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.

Managing scaphoid fractures. How we do it?

The scaphoid is the common carpal bone to be fractured. Proper clinical and radiological evaluation is required to establish it's diagnosis. The management of acute fractures includes conservative treatment with cast in minimally displaced to open reduction and internal fixation in case of displaced ones. The established nonunion requires open reduction, bone grafting and internal fixation.

Early experience with (dry) arthroscopic 4-corner arthrodesis: from a 4-hour operation to a tourniquet time

PURPOSE

Scaphoidectomy and 4-corner arthrodesis (4CA) is an effective procedure for treating several degenerative conditions of the wrist. Recently, the arthroscopic approach to this operation was described. Although it is conceptually appealing, certain aspects make its application difficult. We present our technique for dry arthroscopic scaphoidectomy and 4CA, which reduces the operative time to less than 2 hours.

METHODS

Four consecutive patients underwent scaphoidectomy and 4CA. In each case, we performed the operation with a dry arthroscopic technique using cannulated screws for rigid fixation. We performed bone grafting from the distal radius in 2 patients and from the scaphoid itself in the other two. The relevant operative details are the use of a scapholunate portal, the resection of the scaphoid with a pituitary rongeur, and the placement of bone graft in a dry arthroscopic environment. Range of motion exercises are started 2 to 3 weeks after the operation.

RESULTS

The first operation took 4 hours. The last 2 were completed in 1 hour 45 minutes and 1 hour 55 minutes, respectively. No complications occurred. No operations were converted to an open procedure.

CONCLUSIONS

Although the operation has a steep learning curve, it is conceptually appealing. It is too early to prove that the arthroscopic procedure has better results than the open 4CA; nevertheless, in our opinion it represents the future of wrist surgery.