Ulnar Head Research Articles

Computer-assisted correction of incongruent distal radioulnar joints in patients with symptomatic ulnar-minus variance

Our study described a computer-assisted, three-dimensional (3-D), planned surgical technique of a radial shortening osteotomy. The osteotomy of the distal radius was planned with computer assistance on 3-D bone models based on computed tomography data. The objective was to maximize the contact zone of the sigmoid notch with the ulnar head. Between 2012 and 2020 we treated 14 wrists in 11 patients with symptomatic ulnar-minus variance with a mean follow-up of 44 months (range 8 to 98) and a mean age of 28 years (range 19 to 38). Postoperatively, patients showed a decrease in pain at rest and during effort (numeric rating scale from 4.4 to 0 and 7.5 to 4.5, respectively). The range of motion postoperatively was similar to the contralateral side. Grip strength increased from 24 kg to 30 kg. The Disability of the Arm, Shoulder, and Hand and the Patient-Rated Wrist Evaluation scores were 28 and 35 postoperatively, respectively. Our technique of 3-D computer-assisted distal radioulnar joint reconstruction led to a pain reduction and improvement of the hand function in patients with symptomatic ulnar-minus variance.Level of evidence: IV

3D analysis of the distal ulna with regard to the design of a new ulnar head prosthesis

Study designA retrospective, single center, data analysis.ObjectivePersistent pain and instability are common complications after distal ulnar head arthroplasty. One main reason may be the insufficient representation of the anatomical structures with the prosthesis. Some anatomical structures are neglected such as the ulnar head offset and the ulnar torsion which consequently influences the wrist biomechanics.MethodsCT scans of the ulnae of forty healthy and asymptomatic patients were analyzed in a three-dimensional surface calculation program. In the best fit principle, cylinders were fitted into the medullary canal of the distal ulna and the ulnar head to determine their size. The distance between the central axes of the two cylinders was measured, which corresponds to the ulnar offset, and also their rotational orientation was measured, which corresponds to the ulnar torsion.ResultsThe mean medullary canal diameter was 5.8 mm (±0.8), and the ulnar head diameter was 15.8 mm (±1.5). The distance between the two cylinder axes was 3.89 mm (±0.78). The orientation of this offset was at an average of 8.63° (±15.28) of supination, reaching from 23° pronation to 32° supination.ConclusionWith these findings, a novel ulnar head prosthesis should have different available stem and head sizes but also have an existing but variable offset between these two elements. A preoperative three-dimensional analysis is due to the high variation of offset orientation highly recommended. These findings might help to better represent the patients natural wrist anatomy in the case of an ulnar head arthroplasty.Level of EvidenceIII.

Bone Morphology in Ulnar Impaction Syndrome: A Radiographic Evaluation.

Background: Positive ulnar variance (UV) may be associated with a higher incidence of ulnar impaction syndrome (UIS). However, neutral and/or negative UV has also been associated with the development of UIS; therefore, other risk factors may be involved. The purpose of this study was to compare radiological bone morphology in patients with UIS and asymptomatic controls. Methods: Between 2009 and 2018, posteroanterior wrist radiographs of 47 wrists in 45 patients diagnosed with UIS were compared with those of 163 wrists in 93 asymptomatic patients from the control group. The following parameters were obtained: ulnar variance (UV); ulnar head top-fovea distance (UTFD); capitate-triquetrum distance (CTD); radio-lunate distance (RLD) and lunate coverage ratio (LCR). The morphology of the lunate was classified based on the absence (type I) or presence (type II) of a medial facet that articulates with the hamate. The radiographic parameters and lunate types were compared between the two groups. We then divided the groups into two subgroups: the positive UV subgroup and the neutral/negative UV subgroup. In each subgroup, the radiographic parameters and lunate types were compared between the UIS and control groups. Results: In the UIS group, the UV and UTFD were significantly increased compared to those in the control group. The proportion of type II lunates was significantly higher in the UIS group than in the control group. In addition, the type II lunate was more common in the UIS group in both the positive UV and negative UV groups. Conclusions: Our study suggests that in addition to positive UV, ulnar head morphology with an increased UTFD and type II lunate morphology may be associated with the development of ulnar impaction syndrome. Level of Evidence: Level III (Diagnostic).

Radiological Outcomes of the Simplified Sauvé-Kapandji Procedure for Osteoarthritis of the Distal Radioulnar Joint.

Background: We have been using a simplified Sauvé-Kapandji (SK) procedure using a headless compression screw for the treatment of osteoarthritis (OA) of the distal radio-ulnar joint (DRUJ). Unlike a standard SK procedure, the simplified SK procedure does not require exposure of the DRUJ to prepare the opposing surfaces of the sigmoid fossa and the ulnar head or any procedures to stabilise the proximal stump of the ulna. The aim of this study is to report the radiological outcomes of the simplified SK procedure. Methods: We retrospectively reviewed data of all patients who underwent a simplified SK procedure for osteoarthritis of the DRUJ at our hospital between October 2008 and September 2020 with a follow-up of at least 25 weeks. Baseline demographic and clinical characteristics were investigated. We also measured radiographic parameters and performed statistical analyses to evaluate the shelf-forming region, ulnar stump and deviation of the carpal region. Results: Our study included 10 patients with a mean follow-up of 52.3 weeks. There was no instance of complications such as nonunion of DRUJ arthrodesis, callus formation at ulnar pseudoarthrosis and painful instability at the proximal stump of the ulna. According to the Wilcoxon signed rank test, no radiographic parameters significantly changed during the follow-up period. There was a significant negative correlation between radioulnar width and the variation of ulnar translation index. Conclusions: All radiographic parameters were well maintained, at least during the short follow-up period. There was no instance of nonunion of DRUJ arthrodesis. The simplified SK with simple headless compression screw insertion may be a reliable method for treating OA of the DRUJ. Level of Evidence: Level IV (Therapeutic).

Twenty-Year Experience With Primary Distal Radioulnar Joint Arthroplasty From a Single Institution

The use of implant arthroplasty in the distal radioulnar joint is increasing. Two main types of implants are commonly used, ulnar head prosthesis (UHP) and hemi or semi-constrained total distal radioulnar joint arthroplasty. The literature consists mainly of small patient series. The purpose of this study was to examine our long-term outcomes of distal radioulnar joint arthroplasty. Patient data were collected in a patient registry from 2000 to 2019. The follow-up included radiographic examination, physical examination, Mayo Wrist Scores, pain level, range of motion, and grip strength. Reoperations were recorded. The implants were a semi-constrained prosthesis and a metallic UHP. The mean age at surgery was 50 years. Patient demographics were similar, but the semi-constrained group had a higher preoperative percentage of instability (85 vs 52 percent). The median follow-up time was 30 months for the semi-constrained implants group and 102 months for the UHP group. A total of 53 primary semi-constrained total joint arthroplasties and 102 UHPs were included. The grip strength and Mayo Wrist Score improved for both the implant groups. Pain reduced in 76% of the patients. Supination improved for the semi-constrained total joint arthroplasty group. Lifting capacity was better in the semi-constrained total joint arthroplasty patients. The unadjusted reoperation rate was 23% for the semi-constrained implants group and 34% for the UHP group. Twenty-two implants were bilateral; these had comparable results to unilateral implants. Kaplan-Meier survival curves demonstrated 94% survival rate for the semi-constrained implants group and 87% survival for the UHP group after 5 years. The risk factors associated with reoperation for the combined implant group included younger age at surgery, previous wrist surgery, ulnar shortening, and wrist fusion. Distal radioulnar joint arthroplasty improved functional outcomes in both the implant groups, but reoperations were frequent. The semi-constrained implants group had better lifting capacity. The bilateral implants had comparable outcomes to the unilateral implants. Therapeutic IV.

Operative Stabilization of Distal Radius Fractures Presenting With Ulnar Head Subluxation/Dislocation Addresses Distal Radioulnar Joint Instability Without Further Stabilization Procedures.

To determine the prevalence of ulnar head subluxation/dislocation in distal radius fracture and to discuss management, surgical outcomes, and relevant anatomy. Urban tertiary care hospital. Two hundred seventy-one patients with displaced distal radius fractures undergoing surgical management were reviewed to determine the incidence of ulnar head subluxation or dislocation using the Mino criteria defined by Mino et al. Postoperative computed tomography and radiographs were assessed for sigmoid notch and distal radioulnar joint (DRUJ) reduction and fracture healing. Range of motion, functional limitation, and pain were documented at final outcome. Of the 271 cases, there were 8 cases of prereduction DRUJ subluxation/dislocation, including 2 frank dislocations and 6 subluxations (2.95%). All were treated with open reduction and internal fixation (ORIF) of the distal radius with a volar locked plate. In addition, 1 patient underwent ORIF of an associated distal ulnar shaft fracture and another, who had a grade 1 open fracture over the distal ulna, underwent open TFCC repair. The remaining 6 patients had closed reduction of the DRUJ without further stabilizing procedures. All had stable DRUJ joints following ORIF, both intra-operatively and at final follow-up. All ulnar heads were located within the DRUJ on post-op computed tomography; using the more sensitive radioulnar ratio there was residual ulnar head subluxation in 5/8 patients. Range of motion and functional outcome were excellent at an average of 133 weeks postoperatively. The DRUJ was stable at long-term follow-up in all patients. Ulnar head subluxation/dislocation is an uncommon injury in the setting of distal radius fracture. When present, it can usually be treated effectively with operative stabilization of the distal radius fracture without further stabilizing procedures. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

An Especially Unique Case of Accessory Flexor Muscles to All Five Digits with Clinical Implications for Occupational Therapy

INTRODUCTIONAnatomical variations in antebrachial musculature are relatively common. Most are asymptomatic, but some develop serious sequelae. Extra tendon structures in the carpal tunnel can cause carpal tunnel syndrome (CTS), accessory muscle attachments can cause symptomatic supernumerary muscle belly (SSMB) syndrome, and compression of the anterior interosseus nerve from overlaying supernumerary muscles can cause anterior interosseus nerve syndrome (AINS). Many studies have reported accessory muscles to the flexor pollicis longus (aFPL) or flexor digitorum profundus (aFDP), but few have examined co‐occurrences of these muscles, and none have documented a case where they collectively send isolated flexion forces to all five digits. The objective of this study is to analyze an especially unique case of accessory flexor muscles to all five digits with respect to CTS, SSMB syndrome, and AINS clinical implications for Occupational Therapy (OT).METHODSOne aFPL and four aFDPs were found co‐occurring during routine cadaver dissection at the University of Nebraska Medical Center. All neurovascular and muscular components within the flexor compartment of the antebrachium were carefully cleaned of extraneous fascia. Contiguous muscles were reflected to view the muscle bellies, tendons, proximal attachments (origins), and distal attachments (insertions) of the aFPL and aFDPs. The aFPL and aFDPs were measured and photographed in situ, and maximal isometric force (Fmax) was calculated for each muscle. The normal FPL and FDP were also analyzed to gauge accessory muscle impact. A review of relevant literature was conducted to discuss clinical implications of these muscles for OT practice.RESULTSA bicipital accessory muscle to FDP, with radial (aFDPr) and ulnar (aFDPu) heads, was discovered adjacent to an accessory muscle to FPL (aFPL). The aFDPr/u and aFPL originated from the coronoid process of the ulna and were innervated by the posterior‐lying anterior interosseus nerve. The aFDPr flexed digits 3 and 4, and aFDPu flexed digits 4 and 5. The aFPL was especially unique: part of its tendon merged with the proximal third of FPL (to flex digit 1) while the remainder continued distal, drawing two additional distinct muscle bellies from FPL (aFDPFPL) and FDP (aFDPFDP) and distributing these adjoining forces to digits 2, 3, and 4 via an aponeurosis in the carpal tunnel. The calculated Fmax for aFPL, aFDPr, aFDPu, aFDPFPL, and aFDPFDP were 3.80 N, 1.22 N, 0.98 N, 2.47 N, and 0.62 N respectively and are used to discuss potentials for eliciting a quadriga effect associated with SSMB syndrome. CTS is discussed as a result of carpal tunnel crowding, and AINS is discussed in regard to neuropathy of FDP (radial half), FPL, and pronator quadratus. Each of these conditions is conferred with their predominant implications for OT intervention and treatment.CONCLUSIONS & SIGNIFICANCEThe present study reports a previously undocumented and especially unique case of accessory flexor muscles to all five digits. Its use as a reference may help OT providers better determine when supernumerary muscles are present in clients being treated for prehension, distal pinch, and digit independence limitations caused by CTS, SSMB syndrome, or AINS and adapt treatment modalities accordingly.

Reconstruction of the distal radioulnar joint with rib perichondrium\xa0\u2013 midterm follow-up

BackgroundReconstruction of an osteoarthritic distal radioulnar joint (DRUJ) in patients with high physical demands and a long lifetime expectancy is challenging. A variety of methods like implant surgery and salvage procedures as partial or total ulnar head resection and the Sauve-Kapandji procedure are reasonable options in the elderly patient but not in young individuals since it often compromises manual power and stability and may cause impingement problems. Reconstruction of the DRUJ with rib perichondrium is a new treatment option with promising short-term outcome. The aim the present study was to investigate if the outcome is consistent over time.MethodsFour female patients with a mean age of 40.5 years suffered severe unilateral osteoarthritis in the DRUJ. They underwent reconstruction of the joint with rib perichondrium transplants. Preoperatively, mean pain under manual load was 8.5 (range 7–10) and 4.2 (range 2–5) at rest, using the visual analogue scale (VAS). Range of motion (ROM) in forearm rotation was on average 118° and grip strength was 86% in comparison to the contralateral hand. The outcome was assessed at a clinical follow-up in 2016, measuring ROM, grip-strength, pain at rest and under manual load and DASH-score. Radiological examination was performed. An additional follow-up by letter was performed in 2021 using a patient-reported-outcome survey (PROS). The patients were asked to grade the ROM and grip-strength as changed or unchanged in comparison to the clinical follow-up in 2016.ResultsAt clinical follow-up at a mean of 3.1 years (range 1–5) after surgery, pain level had decreased to VAS 1.5 (0–5) under load and all patients were pain free at rest. Forearm rotation was on average 156° (range 100–180) and grip strength was 97% of the unoperated hand. The mean DASH-score was 14.4 (0–45). An additional follow-up by letter was conducted at a mean of 7.5 years (5.5–9.5) after surgery. ROM and grip strength were reported as unchanged by all patients in relation to the previous clinical follow-up. No additional surgery or complications were reported.ConclusionReconstruction of the osteoarthritic DRU-joint with rib perichondrium transplantation can provide good clinical outcome with perseverance over time.Level of evidenceIV.

Residual stability of the distal radioulnar joint following ulnar styloid fracture: influence of the remnant distal radioulnar ligaments.

Clinical studies suggest that even untreated basal ulnar styloid fractures may not affect patient outcomes. This may be due to the remaining parts of the distal radioulnar ligament still attached providing sufficient residual stability of the distal radioulnar joint. We tested this hypothesis in a biomechanical cadaveric model. Dorsopalmar translation of the distal radioulnar joint and forearm rotation were measured. Seventeen specimens were tested after a simulated ulnar styloid fracture including the fovea, followed by transection of the remaining palmar (n = 9) or dorsal (n = 8) portions of the distal radioulnar ligament and finally with all remnants transected. Rotation and translation both increased significantly after the final transection compared with the foveal fracture. The increase in translation was larger after transection of the dorsal remnants. We conclude that in an ulnar styloid fracture including the fovea, some ligament components are still attached to the ulnar head, giving residual stability to the distal radioulnar joint.

Is the Fovea Ulnaris Truly Isometric during Forearm Rotation?—An In Vivo Retrospective Analysis Using Superimpositions of Three-Dimensional Reconstructions

The fovea ulnaris is considered to be the center of rotation on the ulnar head during forearm rotation. The purpose of this study was to investigate whether the fovea ulnaris is truly isometric during forearm rotation in vivo. The three-dimensional reconstruction models of 21 wrist computed tomography images taken in supination and pronation were investigated. The models were superimposed so that the two ulnar heads were in the same position. Numerous points were set on the surface of the ulnar head with a mean distance of 0.2 mm between the nearest two points. Then, the models were superimposed with respect to the radius, and the distance between the same points on the ulnar head in pronation and supination (DFR) was measured. The rotation center was defined as the point with the shortest DFR. The isometric point was defined as a rotation center with a DFR of less than 0.2 mm. An isometric point was found in three cases and not in 18 cases. The distance the rotation center moved during forearm rotation (DFR of the rotation center) ranged from 0.1 mm to 2.4 mm. The position of the rotation center in the radioulnar direction was significantly correlated with the translation of the ulnar head and the amount of forearm rotation. The rotation center was located more ulnarly when the translation of the ulnar head or the amount of forearm rotation was greater. The isometricity of the foveal insertion of the TFCC during forearm rotation may not be consistent in vivo. The center of rotation on the ulnar head during forearm rotation appears to shift ulnarly with increasing translation of the ulnar head or forearm rotation.

Outcomes following Distal Radioulnar Joint Arthroplasty in the Setting of Total or Partial Wrist Fusion.

Purpose To evaluate the functional outcome and complications following primary ulnar head or total distal radial ulnar joint (DRUJ) arthroplasty in patients who have a partial or total wrist fusion. Methods We conducted a retrospective review of 33 primary DRUJ implants in 31 patients who had a partial or total wrist fusion. Follow-up time averaged 67 months. There were 11 partial and 22 total wrist fusions with 22 ulnar head prosthesis and 11 total DRUJ implants. The mean age of the patients was 49 years. Eighty-one percent had previous surgeries with an average number of 4.6 previous wrist procedures. Pre- and postoperative pain levels were recorded. Mayo Wrist Scores were calculated. Grip strength, range of motion (ROM), and post-operative complications were noted. Results The pain scores improved in 67% of the patients. The Mayo Wrist Score improved significantly from a mean of 39 preoperatively to 51 postoperatively. The grip strength and pro-supination remained stable. The wrist ROM also remained stable in the patients with partial wrist fusions. During the follow-up period, 10 (30%) of the DRUJ implants were explanted, with a trend toward higher explantation rates in total wrist fusions with one in the partial fusion group and nine in the total wrist fusion group. Four of the explantations happened in the first postoperative year. Nineteen (61%) of the patients required a second surgery for a DRUJ implant-related complication; this rate was similar between the partial and total fusion groups. Conclusions DRUJ replacement resulted in improved pain scores and Mayo wrist scores in the majority of patients; however, the combination of primary DRUJ arthroplasty and total wrist fusion was associated with high complication rates. Surgeons should be aware of the high complication rate seen with DRUJ arthroplasty when combined with total wrist fusion.

Doppler Signal and Bone Erosions at the Enthesis Are Independently Associated With Ultrasound Joint Erosive Damage in Psoriatic Arthritis.

To explore the association of the Outcome Measures in Rheumatology ultrasound (US) entheseal abnormalities with the presence of US joint bone erosions in psoriatic arthritis (PsA). Consecutive patients with PsA were included in this cross-sectional study. Demographic and clinical variables were collected. A bilateral US assessment was carried out at the following entheses: plantar fascia, and the quadriceps, patellar (proximal and distal), and Achilles tendons. The following US entheseal abnormalities were registered: hypoechogenicity, thickening, Doppler signal < 2 mm from the bony cortex, calcification/enthesophyte, and bone erosion. The presence of US joint bone erosions was investigated at the second and fifth metacarpophalangeal joints, ulnar head, and fifth metatarsophalangeal (MTP) joint, bilaterally, as well as at the level of the most inflamed joint on physical examination. Multiple linear regression analysis was performed to identify clinical and/or US variables associated with US-detected joint bone erosions. A total of 104 patients with PsA were enrolled. At least 1 joint bone erosion was found in 47 of 104 patients (45.2%). Bone erosions were most frequently detected at the fifth MTP joint level (42/208 joints [20.2 %] in 32/104 patients [30.8%]). In the multivariate model, only a power Doppler (PD) signal at the enthesis (P < 0.001, standardized β = 0.51), bone erosions at the enthesis (P = 0.02, standardized β = 0.20), PsA disease duration (P = 0.04, standardized β = 0.17), and greyscale joint synovitis (P = 0.03, standardized β = 0.42) were associated with US-detected joint bone erosions. PD signal and bone erosions at the enthesis represent sonographic biomarkers of a more severe subset of PsA in terms of US-detected joint erosive damage.

Bone Remodeling after Ulna Head Replacement in Distal Radioulnar Joint Arthroplasty: A Radiographic Comparison between a Partial and a Total Ulna Head Concept.

Background Ulna head arthroplasty has become an eligible solution for injury or disease in the distal radioulnar joint. Bone resorption beneath the prosthetic head is often reported, but mechanism poorly understood. Purpose The aims were to evaluate bone remodeling and radiological instability in two conceptually different distal radioulnar joint arthroplasties: the total and the partial ulna head replacement. Patients and Methods We conducted a retrospective radiographic assessment of 51 ulna head arthroplasties; 26 Herbert ulna (total ulna head replacement) and 25 First Choice (partial ulna head replacement), to analyze periprosthetic bone resorption and radiologic instability. Intraoperative/immediate postoperative and 1-year radiographs were reviewed by two independent assessors. The radiographic follow-up averaged 13 (10-17) months. The size of the stem in relation to the diameter of the ulna (filling ratio) was measured on the intraoperative/immediate postoperative radiographs. Bone resorption beneath the collar of the prothesis was measured on the 1-year radiographs and expressed as a bone resorption index (BRI) between the length of the resorption and the length of the implant stem. Radiological stability was measured on both the preoperative and the 1-year lateral radiographs. Results The total ulna head prothesis presented with more extensive bone resorption beneath the prosthetic head than the partial ulna head prothesis at 1-year post surgery ( p <0.001). The filling ratio did not influence the 1-year bone resorption and there was no difference regarding radiological instability between the two prosthetic designs. Conclusion The pattern of bone adaptions after an ulna head prothesis may differ due to design and concept of the prosthesis.

Outcome of Monteggia Fracture Dislocation in Children Treated With K Wires in Nepalgunj Medical College

Introduction: Monteggia fracture dislocations are rare injuries (&lt;5%) where missed treatment results into deformity and dysfunction of forearm and hand. For the better functional result early diagnosis, accurate reduction of radial head and rigid fixation of ulna and immobilization during post-operative period for ligamentous healing around radius is vital. So operative treatment has been the primary method of treatment to prevent deformity and disability in monteggia fracture dislocation.&#x0D; Aims: The aim of this study was to evaluate the time taken to unite fractures, complications encountered and assess the functional outcome on the basis of K-wire fixation in monteggia fracture dislocation in children.&#x0D; Methods: A cross-sectional observational study was conducted in Nepalgunj Medical College and Teaching Hospital, Kohalpur, Banke with monteggia fracture dislocation in children.&#x0D; Results: Thirty-two monteggia fracture dislocation in children between six to 14 years of age were treated with intramedullary K-wires after reduction of radial head. Seven cases had open reduction, and five needed trans-capitellar K-wire supplementation. Mean union time was 8.44±1.94 weeks ranging from seven to 12 weeks. The functional outcome on the basis of Anderson’s scoring system was excellent in 25(78.1%), good in three and optimal in four cases.&#x0D; Conclusion: Monteggia fracture dislocation is better treated early and early mobilization of elbow joint is needed for better functional results.

Radiographic Determination of the Distal Ulnar Diaphyseal Angle

Characterizing the distal ulnar diaphyseal angle (DUDA) may be important for anatomic recreation of the distal ulna during ulnar shortening osteotomy procedures using conventional straight plates. This study characterized the DUDA and determined side-to-side, age, and sex effects on DUDA magnitudes and locations. Retrospective analyses of bilateral wrist radiographs were performed on 60 patients. The DUDA was defined as the angle of intersection between a line passing through the center of the distal ulnar metadiaphyseal region, in line with the landmarked long axis of the ulna, on a lateral radiograph. This inflection point was measured from the most distal aspect of the ulnar head and recorded as the DUDA tip-to-apex distance (TAD). Rater reliability was determined using the intraclass correlation coefficient. We found DUDAs in 94% of radiographs. The mean DUDA angle was 5.6° ± 2.6° and the mean TAD was 45.3 ± 9.5 mm. The Pearson correlation coefficients for side-to-side comparisons were 0.47 for the DUDA angle and 0.69 for the TAD. For male and female patients, the mean DUDAs were 5.4° ± 2.3° and 5.9° ± 2.9°, respectively, and the mean TADs were 47.8 ± 9.7 mm and 41.7 ± 7.9 mm, respectively. The DUDA angle and TAD had negligible associations with age (r=-0.15 and-0.08, respectively). At 0.74 (95% CI, 0.58-0.85), interrater reliability was good. At 0.93 (95% CI, 0.88-0.96), intrarater reliability was excellent. We demonstrated DUDAs, representing valgus deviations from the center axis and anteroposterior views of the ulna. Contralateral lateral wrist radiographs are moderate to strongly reliable in determining a DUDA. Rater reliability was good to excellent. Re-creation of the DUDA may benefit procedures such as ulnar shortening osteotomy, fractures, or malunion by contributing to knowledge of distal radioulnar joint biomechanics.

A case of ulnar head dislocation with radial head dislocation

A case of ulnar head dislocation with radial head dislocation

Median Nerve Passing below the Ulnar Head of Pronator Teres in Cadavers of a Medical College in Western Nepal: A Descriptive Cross-sectional Study.

Median nerve passes between two heads of pronator teres muscle while passing through the elbow. Detailed knowledge of these variations in the course of Median Nerve in relation to pronator teres and its neighboring structure is required for diagnosis of pronator syndrome. The aim of the study is to find out the proportion of Median Nerve passing below the ulnar head of pronator teres in cadavers of a medical college in Western Nepal. A descriptive cross-sectional study was carried out at the Department of Anatomy in a medical college of Nepal from 20th July 2021 to 2nd September 2021 after ethical clearance from the same institution (Reference number: UCMS/IRC/079/21). Variations in the course of the median nerve while passing through pronator teres were observed, recorded and photographed. Convenience sampling method was used. Data were analyzed using Microsoft Excel 2016. Point estimate at 95% Confidence Interval was calculated along with frequency and percentage. Out of 54 prosected specimens of upper limbs, 4 (7.40%) (0.418-14.38 at 95% Confidence Interval) Median Nerve passed below the ulnar head of pronator teres muscle and in 50 (92.60%) specimens Median Nerve passed between two heads of pronator teres. Our study shows that the median nerve passed below the ulnar head of pronator teres muscle is higher as compared to other studies done in similar settings. Thus, knowledge of variations in the course of Median Nerve in elbow has immense importance in the academic and clinical arena.

Ulnocarpal Impaction.

Ulnocarpal impaction syndrome is a common cause for ulnarsided wrist pain caused by an abutment between the ulnar head and the lunotriquetral complex. This pain is typically triggered by load bearing and rotation of the forearm. Radiographic examination is often associated with positive ulnar variance and cysts in the lunate, edema of the ulnoproximal lunate is shown in MRI. Operative treatment aims to reduce load on the lunate, either by open ulnar shortening osteotomy or arthroscopic wafer procedure.

157 Non-Surgical Management of an Acute Isolated Volar Dislocation of the Distal Radio-Ulnar Joint

Abstract Isolated distal radio-ulnar joint dislocations are rare and commonly missed on radiographs. A young male presented with severe pain and deformity of the left wrist, following a collision whilst playing rugby. This was easily diagnosed using plain radiographs, and the initial attempted reduction methods in the Emergency Department failed. The patient was subsequently anaesthetised in theatre, yet reduction by an accepted method of palmar to dorsal pressure over the interosseous membrane with simultaneous distraction of the wrist failed. A further attempt to manipulate the dislocated ulnar head was successful, with the same force applied whilst the wrist was maximally flexed and pronated – thereby avoiding an open reduction. The patient was asymptomatic at final follow-up, over one year later. This technique has not previously been described in the literature and may be used in similar injuries in the future.

Clinical, radiological and patient-rated outcome comparison between total and partial ulnar head implants.

This study aimed to analyse the clinical and radiological outcomes after ulnar head replacement and to compare partial and total ulnar head implants. Twenty-two patients with 23 implants were available with a mean follow-up time of 7years (range 1.3 to 17) after distal radioulnar joint arthroplasty. At the final follow-up, patients had a low level of pain at rest and during effort, a median Disabilities of the Arm, Shoulder, and Hand (DASH) score of 12 and Patient-Rated Wrist Evaluation score of 12 with partial ulnar head implants, and scores of 20 and 22 in total ulnar head implants, respectively. While the range of motion in patients with partial ulnar head implants was slightly reduced in comparison with the preoperative condition and to the patients with total ulnar head implants, there was a tendency to a higher grip strength and rotational torque. Both types of prosthesis showed sigmoid notch resorptions and resorptions around the neck. We conclude that the results after partial ulnar head replacement do not significantly differ from the total ulnar head implants in many aspects.Level of evidence: III.