Dorsal Intercalated Segment Instability Research Articles

A comparative study of volar locking-plate fixation with corticocancellous and pure cancellous bone grafts for scaphoid nonunion with dorsal intercalated segmental instability secondary to scaphoid humpback deformity

IntroductionBone grafts for scaphoid nonunion with deformity include cortcicocancellous or pure cancellous bone grafts. This study compared the outcomes between two types of bone grafts when employing a volar locking-plate in patients with scaphoid nonunion with dorsal intercalated segmental instability (DISI). Patients and MethodsThis retrospective study included 34 patients with scaphoid nonunion and DISI due to humpback deformity treated between March 2017 and January 2022. Two types of bone grafts were obtained from iliac crest. Twenty of the corticocancellous (CC) group underwent a wedge-shaped graft, while 14 patients of the pure cancellous (C-only) group received graft chips. In both groups, a 1.5-mm anatomically pre-contoured locking plate was used for fixation. Radiographic evaluations included the union rate and carpal alignment including scapholunate angle (SLA), radiolunate angle (RLA), intrascaphoid angle (ISA) and scaphoid height to length ratio (HLR). Clinical assessments encompassed wrist range-of-motion, grip strength, and patient-reported outcomes. ResultsNineteen of the 20 patients in the CC group and 12 of the 14 patients in the C-only group respectively, achieving osseous union. The mean follow-up period in CC group was 14.7 (range, 12 ∼ 24) months and that in C-only group was 12.6 (range, 12 ∼ 15) months. Postoperatively, there were no significant intergroup differences of radiographic parameters including SLA (CC; 49.9° ± 6.7° vs. C-only; 48.9° ± 3.5°, P = 0.676), RLA (1.7° ± 6.4° vs. 2.4° ± 3.3°, P = 0.74), ISA (36° ± 7.5° vs. 36.6° ± 12.2°, P = 0.881), and HLR (0.54 ± 0.09 vs. 0.53 ± 0.05, P = 0.587). Clinical outcomes, including the flexion–extension arc (137° ± 30° vs. 158° ± 33°, P = 0.122), grip strength (93.4 % ± 15.4% vs. 99.5 % ± 16.7 %, P = 0.39), Quick Disabilities of the Arm, Shoulder, and Hand scores (11.2 ± 8.3 vs. 12.5 ± 7.7, P = 0.74) and Mayo Wrist Scores (81.2 ± 13.1 vs. 89 ± 11.4, P = 0.242) also showed no significant intergroup differences. ConclusionsVolar locking-plate fixation with pure cancellous bone grafts achieved outcomes comparable to those achieved with corticocancellous bone grafts in scaphoid nonunion with deformity, possibly due to the biomechanical advantages of the volar plate to provide structural supports.

Retrospective analysis of scaphoid trapezium pyrocarbon implant intervention in STT arthritis: a 3-year follow-up study.

The purpose of this study was to evaluate clinical, patient rated and radiological outcome of the scaphoid trapezium pyrocarbon implant (STPI) at a minimum of three years follow-up. Consecutive patients operated with the STPI due to scaphotrapeziotrapezoidal (STT) arthritis between 2012 and 2019 were included. Patients were evaluated preoperatively and annually after surgery for range of motion, grip strength, key pinch, quick-DASH, pain, and satisfaction. Radiographs were evaluated for implant position, signs of dorsal intercalated segment instability (DISI), capitolunate (CL) angle, scapholunate (SL) distance, and presence of osteophytes. Twenty-six patients (29 implants) were included. Seven implants were revised during the follow up, mainly due to pain: three implants were removed, four patients received a new STPI of a different size, leaving 22 implants in 20 patients available for follow up, 9 males and 11 females. Median age was 61.7 years (51-78 years). Median follow-up time was 68 months (37-105 months). Comparing preoperative status to the last follow-up, wrist extension and deviation, thumb abduction, and grip strength did not change. Key Pinch, quick DASH, pain, and patient satisfaction improved significantly at last follow-up. Radiographic signs of DISI were seen in six cases preoperatively and in 12 cases at last follow-up. At a minimum of three years follow-up, the STPI used for STT-arthritis improve pain, quick-DASH result, and patient satisfaction significantly. ROM and grip strength did not change compared to preoperative values. Radiographic signs of carpal instability were common at the follow-up and the revision rate was high.

Scaphoid Length Loss Following Nonunion Is Associated with Dorsal Intercalated Segment Instability.

Background Dorsal intercalated segment instability (DISI) in scaphoid nonunions is frequently attributed to fracture location relative to ligamentous attachments onto the scaphoid apex. We hypothesize scaphoid length loss to have a stronger correlation with DISI deformity than fracture location in patients with scaphoid nonunion. Questions/Purposes To investigate the correlation between (1) scaphoid length loss, (2) fracture location relative to the scaphoid apex, and (3) type of nonunion (Herbert classification) and DISI deformity in skeletally mature patients with scaphoid nonunion. Patients and Methods Twenty-seven cases of computed tomography (CT)-confirmed scaphoid nonunion (>6 months) were retrospectively included. Our primary outcome was the degree of DISI as measured by the radiolunate (RL) angle on CT. Scaphoid length loss was expressed as height-to-length (H/L) ratio. Fracture location was classified as proximal or distal to the scaphoid apex. Nonunions were classified as fibrous unions (type D1) or pseudoarthrosis (type D2). The correlation between RL angle, H/L ratio, fracture location, and nonunion type was evaluated. Results H/L ratio was the only factor associated with the degree of DISI as measured by RL angle. As scaphoid length loss increased (increasing H/L ratio), the RL angle increased. There was no significant difference in RL angle between fractures located proximal (30 degrees) or distal (28 degrees) to the scaphoid apex, or type D1 (31 degrees) versus type D2 (28 degrees) nonunions. There was no correlation between patient age, sex, or wrist side affected and RL angle. Conclusions Scaphoid length loss, rather than fracture location, is correlated to the degree of DISI deformity in patients with scaphoid nonunion. This highlights the importance of restoring scaphoid height when planning scaphoid nonunion reconstruction. Level of Evidence Level III, diagnostic study.

The onset, progress and factors influencing degenerative arthritis of the wrist following scaphoid fracture non-union

Scaphoid non-union causes osteoarthritis but factors associated are poorly understood. We investigated the rate of osteoarthritis after scaphoid fracture non-union, and if duration and fracture location influenced arthritis and its severity. This retrospective cross-sectional observational study of 278 consecutive cases with scaphoid fracture non-union retrieved data on demographics, non-union duration, fracture location, dorsal intercalated segment instability (DISI), severity and distribution of wrist arthritis. Patient Evaluation Measure (PEM) and Quality of Life assessed impact on patients. Regression models investigated prediction of osteoarthritis by different variables. Time-to-event analysis investigated osteoarthritis evolution. Missing (MAR) data for the PEM and QoL was imputed and analysed. 278 patients, 246 males, aged 27.9 years (range 11 to 78 years), with a scaphoid fracture non-union confirmed on computed tomography (CT) scans (243) and plain radiographs (35) were reviewed. The interval between injury and imaging was 3.3 years (SD 5.9 years; range 0.1-45). The fracture was proximal to the ridge in 162, distal to the ridge in 83 and in the proximal 20% in 33. DISI (RLA ≥ 10°) occurred in 93.5% (260/278). Osteoarthritis was identified in 62.2% (173/278), and we classified a SNAC pattern in 93.6% (162/173). Of these, 100 (61.7%) had SNAC 1, 22 (13.6%) SNAC 2, 17 (10.5%) SNAC 3, and 23 (14.2%) SNAC 4. The mean duration in years for SNAC 1, 2, 3 and 4 were 2.5, 6.0, 8.2, and 11.3 years respectively. In fractures proximal to the ridge, 50% had arthritis in 2.2 years. Whereas in proximal pole, and distal to the ridge, 50% developed in 3.8 and 6.6 years, respectively. The PEM score was 42.8% (SD 18.9%) in those without arthritis and 48.8% (SD 21.5%) in those with arthritis. The mean QoL was 0.838 in patients without SNAC and 0.792 with SNAC. Scaphoid fracture non-union caused early carpal collapse, majority had osteoarthritis usually observed within a year following injury and occurred earliest in proximal waist fractures. Distribution of osteoarthritis (SNAC stage) may not always follow a distinctive pattern, as previously described.

Radiologic Evolution after Scapholunate Dorsal Capsulodesis for Chronic Tears.

Background Many debates are still ongoing for the management of chronic scapholunate (SL) injuries. We have proposed an arthroscopic technique of dorsal capsulodesis with good clinical results. We now propose a radiological follow-up. Purpose To determine if arthroscopic dorsal capsulodesis can improve the radiographic SL angle and maintain this correction over time. Methods From January 2020 to January 2021, we included every patient with an SL instability and sorted them according to the European Wrist Arthroscopy Society (EWAS) classification. All patients had bilateral X-rays with a measurement of the radiolunate (RL) and SL angles for both the pathologic and healthy side. We also included patients with lunotriquetral or triangular fibrocartilage complex lesions. The exclusion criteria were the presence of arthritis and persistent intraoperative SL instability after capsulodesis. An arthroscopic dorsal capsulodesis was performed in all patients as originally described by Mathoulin. The RL and SL angles were then again measured on the immediate postoperative X-ray, and then again at 3, 6, and 12 months postoperatively. The statistical analysis was done using a paired Student's t -test with 145 degrees of freedom and α = 0.05. Results We included a total of 146 patients with a 1-year follow-up. Both the RL angle and the SL angles approach the healthy side at 12 months postoperatively. The RL angle has increased from -7.23 degrees to 4.37 degrees; the difference is still statistically significative, but it is almost equal to the healthy side (5.16 degrees). The SL angle has lowered from 74.55 to 54.95; the difference is still statistically and radiologically significative (6.788 degrees) but has been lowered by 74.3%. Conclusion This study shows that this technique can normalize the dorsal intercalated segment instability (DISI) over time without the need for any pinning or invasive ligament reconstructive surgery. Level of Evidence Level IV, cohort study. Clinical Relevance Dorsal capsulodesis should be considered in all reducible SL injuries, even when DISI is present.

Arthroscopic Management of the Hamate Proximal Pole Arthrosis.

In this retrospective study, all patients with arthrosis of the proximal pole of the hamate encountered in a 10-year period treated with arthroscopy were reviewed. Patient demographics, arthroscopic details, associated injuries, and procedures were reviewed. Functional and patient-reported clinical outcomes after arthroscopic osteochondroplasty were analyzed. An analysis of 39 patients who underwent arthroscopic osteochondroplasty showed a type II lunate prevalence of 87.2%. On wrist arthroscopy, a triangular fibrocartilaginous complex tear was the most common diagnosis (64.1%), followed by scapholunate ligament tear (61.5%) and lunotriquetral ligament tear (35.9%). All patients were managed arthroscopically with 100% procedural success. Average follow-up of 42.8 ± 37.7 months showed statistically significant improvements in the visual analog score and Mayo wrist score postoperatively (P < 0.01). Three patients (7.7%) failed the procedure at a mean of 23 ± 31.4 months. Risk factors for salvage operations were nondominant wrist involvement 100% (P = 0.04), lunotriquetral ligament injury 100% (P = 0.04), the absence of triangular fibrocartilaginous complex injury 100% (P = 0.04), and the presence of scapholunate advanced collapse 100% (P < 0.01). Wrist arthroscopy is valuable for accurately diagnosing and treating hamate arthrosis and identifying a wide variety of pathologies associated. This study showed arthroscopic osteochondroplasty produced satisfactory clinical results. Furthermore, the presence of scapholunate advanced collapse wrist offers its prognostic value in determining treatment failure.

Comparative analysis of scaphoid nonunion treatment with screw fixation and angular stable plate.

Scaphoid fractures represent 5-10% of nonunion rate and the treatment options consist of an open reduction with correction of deformity, restoration of the scaphoid length with autologous wedge grafting and fixation. However, there is still no consensus in the literature on the best fixation method. Therefore, the purpose of the study is to compare plate fixation and screw fixation in treating scaphoid nonunion with humpback deformity and carpal instability. Prospective, non-randomised study comparing the treatment of two groups of patients with scaphoid nonunion. A total of 19 patients were included in the study, the first ten patients were included in group 1 (plate fixation), subsequently nine patients were included in group 2 (screw fixation). The nonunion duration was longer than 6months and patients did not present type III Scaphoid Nonunion Advanced Collapse (SNAC). Clinical evaluations included pain intensity, range of motion, grip strength, pinch test and functional scales Disabilities of the Arm, Shoulder and Hand (DASH) and Mayo Wrist Score. Radiographic evaluations consisted of radiographs of both wrists in AP, AP with ulnar deviation, lateral and oblique views. Patients further underwent a tomography of the affected wrist for bone deformity, carpal collapse and later consolidation evaluation. According to post-operative measurements, group 1 showed a significant improvement in the scapholunate angle (p = 0.011) and in the intrascaphoid angle (p = 0.002). Group 2 only showed an improvement in the scapholunate angle (p = 0.011). All patients in group 1 achieved consolidation in 8weeks, while group 2 patients had a slower consolidation, with a mean of 14weeks and standard deviation (SD) of 4.2, with statistical significance (p = 0.006). Our prospective study, despite the limitations, contributes to the literature for demonstrating a better fixation using plate, with a better correction of humpback deformity and Dorsal Intercalated Segment Instability (DISI) and a faster consolidation. II, therapeutics studies; prospective comparative study.

Non-traumatic scapholunate dissociation in a 10-year-old female: A case report

IntroductionSevere or minor repetitive trauma, inflammation, infection, tumors, and congenital ligamentous laxity have been etiologically implicated in scapholunate dissociation (SLD). While a few cases of patients with asymptomatic SLD have been reported in the literature, despite radiographically demonstrated widened scapholunate angles and rotatory subluxation of the scaphoid bone, these patients experienced only mild or no pain and no dorsal intercalated segment instability deformity. Here, we report the case of a monolateral non-traumatic SLD in a young 10-year-old girl that led to an important range of motion impairment with no wrist pain. The case represents a rarity for no previous history of trauma, young age, and no pain.Main symptoms and important clinical findingsIn our patient, an examination revealed a reduced range of motion in the left wrist and no pain during passive or active mobilization. The X-ray showed a 16 mm scapholunate gap in the anteroposterior roentgenogram. In this case, we suggested that congenital or developmental ligamentous laxity may be the cause of SLD. The diagnostic assessment was completed with a wrist MRI and CT.Therapeutic interventions and outcomesThe patient underwent an open dorsal surgery: we directly reduced the dislocated bones and fixed them with five percutaneous 1 mm k-wires. Finally, the scapholunate ligaments were repaired using bone-absorbable anchor sutures. The wrist was immobilized in a volar cast for 8 weeks. The patient was able to resume her daily life activities (included sport) within 12 months.ConclusionCarpus injuries are rare in children, and treatment, especially for young-age patients, is fraught with risks and remains controversial. Our case demonstrates that the patient has had a good clinical outcome. The physio-rehabilitation program for this patient has been of long duration. Most previous studies have shown excellent clinical results after an average of 2.4 years.

The INCA® implant to treat isolated scaphotrapeziotrapezoid osteoarthritis: Preliminary results at a minimum 2 years’ follow-up

We report results with the INCA® distal scaphoid pole resurfacing implant anchored within the scaphoid for isolated scaphotrapeziotrapezoid osteoarthritis. Thirty-five implants in 27 patients (mean age, 69 years) were retrospectively included with a minimum follow-up of 2 years. Outcome criteria were pain (VAS), PROMs (QuickDASH, PRWE and MMWS), wrist motion, pinch and grip strength, and radiographic assessment. The average follow-up was 4.6 years. There was a significant improvement in pain, PROMs, grip and pinch strength. Radial deviation and wrist extension showed slight but significant postoperative decrease (−4° for both). Dorsal intercalated segment instability (DISI) was significantly improved postoperatively (7 cases versus 21 preoperatively). There were 2 cases of implant loosening (6%) within the first 10 months: 1 keel malpositioning and 1 insufficient postoperative immobilization. These findings suggest that the INCA® implant is an effective and reliable medium-term solution for isolated scaphotrapeziotrapezoid osteoarthritis. By restoring scaphoid length and gliding on the trapeziotrapezoid surface, the implant contributes to restoring normal bone alignment of the wrist.

Proximal Trapezoidectomy and Scaphotrapezoid Joint Tendon Interposition at the Time of Ligament Reconstruction and Tendon Interposition for Pan Trapezial Osteoarthritis Does Not Increase Proximal Carpal Row Malalignment.

Background Surgical options for osteoarthritis (OA) of the first carpometacarpal include excision, replacement arthroplasty, and arthrodesis. However, in pan trapezial OA, optimal management of residual scaphotrapezoidal articulation has remained unclear. Purpose The purpose of this study was to evaluate whether removing the proximal trapezoid from the scaphotrapezoid joint (STJ) and interposing tendon when performing a ligament reconstruction and tendon interposition (LRTI) for pan trapezial arthritis resulted in any clinical or radiographic compromise compared with LRTI alone in isolated carpometacarpal joint arthritis. Methods In a prospective consecutive cohort, 122 thumbs were selected to generate two matched cohorts and a cross-sectional review was completed at an average of 24 months (range: 5-203 months). Fifty-six thumbs had LRTI alone and 66 thumbs also had resection of the proximal portion of the trapezoid with tendon interposition in the residual gap. Results The cohorts showed no significant differences in subjective and objective outcome measures and imaging. Excision of the STJ was not associated with poorer clinical outcomes or the development of a dorsal intercalated segment instability deformity. Conclusions The management of pan trapezial arthritis with LRTI and proximal trapezoid excision and STJ interposition appears satisfactory on short- to medium-term clinical and radiographic follow-up. Level of Evidence: This is a Level III, consecutive cross-sectional cohort study.

Not-So-Simple Wrist Injury After Fall On Outstretched Hand: Dorsal Intercalated Segment Instability.

Not-So-Simple Wrist Injury After Fall On Outstretched Hand: Dorsal Intercalated Segment Instability.

Arthroscopic reconstruction of scaphoid nonunions

Minimally invasive arthroscopically assisted reconstruction of scaphoid nonunions. Delayed union or nonunion of the scaphoid with sclerosis and with indication for bone transplantation. Limited arthritic changes at the radial styloid. Severe humpback deformity with dorsal intercalated segment instability. Midcarpal arthritic changes. Supine position with the forearm upright and in neutral position, the elbow flexed by90°, axial traction of 3 to 4 kg. Standard wrist arthroscopy via the 3-4 and the 4-5portal and the midcarpal joint via the radial and ulnar portal, respectively, with sodium chloride as arthroscopy medium. Change of the optic to the ulnar midcarpal portal and opening of the nonunion with an elevator via the radial midcarpal portal. Resection of the sclerosis with a3.0 mm burr while irrigating the joint. Harvesting of cancellous bone via the second extensor compartment. On the hand table, closed reduction by joy-stick K‑wires if needed and insertion of K‑wires for the scaphoid screw. Insertion of the screw without entering of the distal thread into the bone. Arthroscopic insertion of the bone transplant by ablunt drill sleeve via the radial portal with steady compression by the obturator. Complete insertion of the screw under arthroscopic control of the compression of the nonunion space with arthroscopic control of stability with the probe. Six weeks forearm cast including the thumb metacarpophalangeal joint, radiographic control and non-load bearing movements for two more weeks, CT scan in the oblique sagittal plane after 8weeks, and increase of load, as well as physiotherapy on demand depending on the radiographic results. To date, 17patients with amean age of the nonunion of 18months were treated. In14patients, bony union was achieved after 8weeks. In one patient, an extraosseous screw placement was corrected. In another patient with extraosseous screw placement, persisting nonunion was treated with an angular stable plate. One scaphoid demonstrated an asymptomatic tight nonunion after 14months, while one scaphoid with sclerosis of the proximal pole did not heal.

Is DISI Deformity Related to Presence of a Medial Lunate Facet in Patients with Scapholunate Dissociation?

Background Lunate morphology has been suggested to influence carpal kinematics. Purpose We investigate a possible relation between presence of a medial lunate facet and dorsal intercalated segment instability (DISI) of the wrist in patients with a scapholunate (SL) dissociation. Methods We retrospectively reviewed patients diagnosed with SL dissociation between 2000 and 2017. Lunate morphology was categorized based on radiographs and magnetic resonance imaging (MRI), as type I or II according to Viegas and Galley. DISI was defined as radiolunate angle > 15 degrees and SL instability as SL angle > 60 degrees. SL distance > 3 mm was considered as widening and carpal height ratio < 0.5 was considered as carpal collapse. We used descriptive statistics to report on SL instability and DISI in patients with Viegas type I and type II lunates. We calculated kappa to determine agreement between radiographs and MRI and to determine inter- and intraobserver agreement. Results Of 119 patient files, 79 wrists met the inclusion criteria of which 25 were type I lunates and 54 type II. Similar spreading of the data of both groups was found regarding DISI, SL instability, and SL widening based on radiographic classification of the lunate, even after adding MRI findings. In the presence of carpal collapse, capitate-to-triquetrum distance was higher. We found a substantial inter- and intraobserver agreement for lunate classification. Conclusion Our results suggest a similar prevalence of DISI deformity or enlarged SL angle in patients with type I or II lunate in presence of SL dissociation. The Viegas classification is a reliable and reproducible classification system. Level of evidence This is a Level III, cross-sectional study design.

Arthroscopic Scapholunate Synthetic Ligamentoplasty

The scapholunate ligament is made of 3 portions: proximal, volar, and dorsal. The latter is the major stabilizer of the scapholunar pair, and its lesion is bound to cause a destabilization of the carpus, as well as scapholunar diastasis, dorsal intercalated segment instability, then eventually SLAC (i.e., scapholunate advanced collapse) wrist. The healing process of this ligament, either spontaneous or after primary repair with direct suture, is rarely observed and a significant number of patients are diagnosed only at a late stage, thus making an illusion of a maintained stability of the carpus first range. Management then consists of ligamentoplasty. Several open techniques are described to restore stability, but at the cost of a frequent and significant tightening of the wrist. We will introduce here an arthroscopic ligamentoplasty technique completed by a posterior capsulodesis.

Evaluation of Carpal Malalignment Before and After Interpositional Bone Grafting for Treating Scaphoid Nonunion

Background: Carpal malalignment following the treatment of scaphoid nonunion increases the risk of Dorsal Intercalated Segment Instability (DISI) and progressive radiocarpal arthrosis. Objectives: In this study, we aimed to investigate the outcome of interpositional bone grafting without preplanning to correct carpal malalignment in treating scaphoid nonunion. Methods: Patients and Methods: In a retrospective study, 96 patients who underwent surgery to treat scaphoid nonunion (interpositional bone grafting without correction of carpal malalignment) were included. Indices of carpal malalignment, including the lunocapitate and scapholunate angles, were assessed before and one year after the surgery. A lunocapitate angle of more than15º and a scapholunate angle of more than 60º were considered a sign of DISI. Results: The study population included 93 men (96.9%) and three women (3.1%) with a Mean±SD age of 26.1±3.1 years. The mean±SD time from fracture to nonunion surgery was 8.6±4.2 months. The Mean±SD lunocapitate angle was 15.2±13.1º before and 14.4±11º one year after the surgery (P=0.48). The Mean±SD scapholunate angle was 63.9±15.2º before and 64.5±14.6º after the surgery (P=0.69). DISI was present in 67 patients (69.8%) before and 66 (68.8%) after the surgery. This difference was not statistically significant, too (P=0.89). Conclusion: Correction of carpal malalignment should be preoperatively planned to treat scaphoid nonunion to reduce the risk of postoperative DISI and subsequent radiocarpal arthrosis.

Comparative Analysis of 3 Techniques of Scapholunate Reconstruction for Dorsal Intercalated Segment Instability

The combination of scaphoid rotatory subluxation, dorsal intercalated segment instability, and dorsal scaphoid translation (DST) constitutes stage 5 scapholunate dissociation in the modified classification system of Garcia-Elias. The purpose of this study was to compare the static radiographic outcomes of reduction and association of the scaphoid and lunate (RASL), three-ligament tenodesis (TLT), and anatomic front and back (ANAFAB) reconstructions for stage 5 scaphoid and lunate malrotation and translation. Stage 5 scapholunate dissociation was created in 15 fresh-frozen specimens by cutting the scapholunate interosseous ligament, long radiolunate ligament, dorsal intercarpal ligament, and scaphotrapeziotrapezoid ligament complex. Specimens were randomized to receive 1 of the 3 reconstructive techniques. Radiolunate angle (RLA), scapholunate angle, scapholunate gap, and DST were measured in static fluoroscopic posteroanterior and lateral views in 3 conditions: baseline, injured, and reconstructed. Reduction and association of the scaphoid and lunate showed an improved correction of scapholunate gap compared with TLT and ANAFAB. Anatomic front and back demonstrated an improved correction in RLA and scapholunate angle compared with RASL but not TLT. When the reconstruction was compared with baseline, there was a persistent lunate extension for TLT (RLA and scapholunate angle) and RASL (RLA); however, no significant difference in any parameter was found with ANAFAB. Anatomic front and back significantly improved DST, whereas TLT and RASL did not. In this cadaveric model of scapholunate dissociation with dorsal intercalated segment instability and DST, each of the 3 repairs had different effects on carpal posture and alignment. While only RASL statistically improved scapholunate gap, only ANAFAB significantly improved DST. Both TLT and RASL improved radiographic parameters; however, each had a persistent increase in the lunate extension following reconstruction. It may be prudent to consider different reconstructive techniques for different stages of scapholunate instability. Anatomic front and back, a repair that addresses both dorsal and volar ligament stabilizers, provides improved reduction of dorsal intercalated segment instability and DST in stage 5 scapholunate dissociation.

Is the Dorsal Fiber-Splitting Approach to the Wrist Safe? A Kinematic Analysis and Introduction of the “Window” Approach

To compare the kinematic effects of the dorsal fiber-splitting approach for scapholunate ligament repair to a dorsal "window" approach that spares all ligaments. We randomized 24 fresh-frozen paired cadaveric forearms to either the dorsal fiber-splitting capsulotomy approach (FSC) or the dorsal window approach (window) following scapholunate interosseous ligament(SLIL) division. Loaded fluoroscopic radiographs were obtained after each of the 4 testing conditions following cyclic loading (200 cycles; 71 N): (1) intact SLIL, (2) SLIL-division, (3) surgical approach, and (4) closure. FSC specimens were randomly allocated to 2 subgroups for closure with either a suture anchor (n= 6) or a simple running suture closure (n= 6). Radiographic parameter measurements included the scapholunate gap, radiolunate angle, scapholunate angle, and dorsal scaphoid translation. Following the FSC, there were significant alterations in all radiographic parameters when compared with the intact and SLIL-division conditions. The window approach did not result in significant changes in any radiographic parameter. When compared to the window approach, all radiographic parameters of the FSC approach were significantly altered. Following closure with suture anchors in the FSC group, radiographic parameters improved, whereas with standard closure they failed to do so. Despite anchor closure, dorsal scaphoid translation, radiolunate angle, and scapholunate angle all remained elevated compared with scapholunate-divided wrists. The FSC produced significant changes in carpal posture under load, including scapholunate diastasis, dorsal intercalated segment instability, and dorsal scaphoid translation in SLIL-deficient wrists. The window approach preserved the critical dorsal ligament stabilizers and did not produce changes in carpal posture. The FSC may create iatrogenic changes in carpal posture that cannot be fully corrected with standard or anchor closure. The window approach does not alter carpal posture and should be considered when performing surgical procedures on the scaphoid or lunate.

Lunate morphology: association with the severity of scapholunate ligament injuries and carpal instability patterns

Type II lunate has been associated with a lower incidence of dorsal intercalated segment instability (DISI) in the case of scapholunate dissociation. We aimed to evaluate the frequency of different lunate types and their influence on the prevalence and severity of scapholunate ligament (SLIL) injuries and the development of DISI. The surgical records of 414 arthroscopies were reviewed retrospectively. Lunate types were diagnosed based on radiograms and MRI examinations. The Type II lunate had a facet between hamate and lunate; in the Type I lunate, this facet is lacking. We additionally included the assessment of the capitate–triquetrum distance (CTD), which defines Type I, Intermediate, and Type II lunates. We adopted the DISI when the scapholunate angle was more than 80° and/or the radiolunate angle less than −15°. Fisher’s exact test was applied to compare the distribution frequency of SLIL lesions and DISI deformity of patients with different lunate types. To quantify the inter- and the intra-rater reliability of lunate type assessment Cohen’s kappa was calculated and, for CTD measurements, a Bland–Altman plot was created. Up to 77.1% patients had Type II lunates. Regarding MRI and CTD classification in patients with Type I lunates, Grade 4 SLIL injuries were more common than in those with Intermediate and Type II (p < 0.05). In the case of Grade 4 SLIL lesions, DISI was more common in patients with Type I lunates (p < 0.05). There were, however, only 25 patients with Type I lunates, and Grade 4 SLIL lesions according to MRI, and 6 according to CTD measurement.

Traumatic Nondissociative Carpal Instability: A Case Series

We report 8 cases of acute or subacute unilateral nondissociative carpal instability (CIND) in the context of nondisplaced scaphoid fractures. Eight patients from 3 centers developed abnormal volar intercalated segment instability (VISI) or dorsal intercalated segment instability (DISI) following the diagnosis of a nondisplaced scaphoid fracture. An operative inspection in each patient confirmed intact scapholunate and lunotriquetral interosseous ligaments. We outline the demographic characteristics of our patient cohort, radiologic and operative findings of CIND-DISI and CIND-VISI, and the outcomes of acute and delayed treatment. Two patients were diagnosed with CIND-DISI and 6 with CIND-VISI associated with ipsilateral nondisplaced scaphoid fractures. The average time from injury to diagnosis of CIND was 11 weeks, and the mean clinical and radiographic follow-up was 18 months. Rapid healing of the scaphoid fractures was achieved in all patients (4 open reduction internal fixation, 4 cast). All patients underwent surgery to improve proximal carpal row alignment: in 3 of the 4 patients who were diagnosed and treated surgically within 12 weeks of injury, the radiolunate angle (RLA) was successfully restored. A contracture release and ligament repair or reconstruction with tendon graft 12 or more weeks following injury was unsuccessful in restoring proximal row alignment in all 4 patients. Two patients in the delayed treatment group required secondary surgery for partial fusion. Based on the arthroscopic, imaging, and operative findings, we propose that the ligamentous restraints to CIND-VISI are dorsal at the radiocarpal joint and volar at the midcarpal joint. Conversely, the ligamentous restraints to CIND-DISI are dorsal at the midcarpal joint and volar at both the radiocarpal and midcarpal joints. In our series, a delayed diagnosis and late reconstructive surgery were associated with no improvement in RLA. We recommend early recognition of traumatic CIND and prompt treatment of injured ligaments prior to the development of a fixed deformity. Therapeutic V.

Posttraumatic Carpal Instability Nondissociative.

Background Posttraumatic midcarpal instability nondissociative (CIND) is an exceptional rare condition, therefore the outcome after different treatment options remains unknown. Questions The purpose of this study was to investigate the different treatment options for posttraumatic CIND. We also describe the different radiological and magnetic resonance imaging (MRI) findings in this patient cohort. Patients and Methods We present outcomes of 10 patients who developed CIND following acute wrist trauma between 2007 and 2018, 3 with dorsal intercalated segment instability pattern (CIND-DISI) and 7 with volar intercalated segment instability (CIND-VISI) radiographically. Results Three patients with CIND-VISI had satisfactory outcomes with conservative treatment. Two patients with irreducible CIND-DISI and one with CIND-VISI underwent proximal row carpectomy (PRC), two with reducible CIND-VISI had radiolunate fusion, and two with secondary osteoarthritis had total wrist fusion. All patients with CIND-DISI needed surgery, whereas only four of the seven patients with CIND-VISI needed surgery. On MRI, all three patients with CIND-DISI had rupture of the radiolunate ligament. Conclusions The data collected in this study may provide the first step toward better understanding of the pathology for this exceptionally rare finding. In CIND-VISI, we have not seen any ligament injury in four patients. Therefore, conservative therapy is more likely to be the first step. In CIND-DISI, we recommend an operative procedure: if detected early, with ligament suture, otherwise by radiolunate fusion, PRC, or total wrist fusion. Level of Evidence This is a Level IV study.