Three-dimensional kinematics of the flexor pollicis longus tendon in relation to the position of the FPL plate and distal radius width

Ultrasonographic evaluation of contact configuration between flexor pollicis longus tendon and the volar prominence of volar plate in patients with distal radius fracture

INTRODUCTION

We classified the contact configuration between the volar prominence of volar locking plate (VLP) and flexor pollicis longus (FPL) tendon using ultrasound (US) into indentation contact and smooth contact, and investigated whether the contact configuration is associated with the flexor tendon attrition.

MATERIALS AND METHODS

Ninety-four patients who underwent VLP removal were included in this study. We assessed pain using visual analogue scale, grip strength, and Disabilities of the Arm, Shoulder and Hand score for clinical evaluations, radial inclination, palmar tilt, ulnar variance, and Soong classification for radiological evaluations, and contact configuration using US at 1 year after VLP fixation. After these evaluations, we removed the VLP with observation for the presence of fibrillation or wear of FPL tendon substance. Subsequently, we classified the patients into either of FPL attrition and FPL intact group.

RESULTS

Twenty-eight patients had indentation contact configuration and 66 patients had smooth contact configuration. The kappa value for inter-observer reliability for the contact configuration was 0.78. Twelve patients were included in the FPL attrition group and 82 in the FPL intact group. There was no significant difference in clinical outcomes and Soong classification between the groups. However, palmar tilt of the flexor tendon attrition group was significantly lower than that of the flexor tendon intact group and the FPL attrition group showed significantly higher indentation contact configuration rate than the FPL intact group. FPL tendon attrition was diagnosed using the contact configuration on US with a sensitivity of 100% and specificity of 80%.

CONCLUSION

This study demonstrated that FPL tendon attrition was significantly associated with indentation contact on US with high sensitivity. Therefore, we recommend selective implant removal in patients with indentation contact configuration.

Computed Tomography and Pathobiomechanical-Based Treatment of Volar Distal Radius Fractures

Today, there are various classifications for distal radius fractures (DRF). However, they are primarily based on plain radiographs and do not provide sufficient information on the best treatment option. There are newer classifications that simultaneously consider the pathobiomechanical basis of the fracture mechanism and analysis of computed tomography images. Main determinants of which type of DRFs occurs are the strength/direction of the applied forces on the carpus and radius, and the position of the wrist relative to the radius during the fall. Reconstruction of the mechanism of injury provides information about which anatomic structures are involved, such as torn ligaments, bone fragments, and the dislocated osteoligamentous units. This article attempts to combine and modify current pathobiomechanically oriented classifications with an improved understanding of the "key fragments" to subsequently offer a treatment approach to stabilize these critical fragments through specific types of internal fixation.

Functional outcomes following fixation of a marginal distal radius fracture with two commonly used volar locking plates: a retrospective cohort study

Introduction

The volar locking plate has been widely used for unstable distal radius fractures to provide early recovery of wrist function. Volar plate prominence to the watershed line has been reported to be related to flexor tendon irritation, and avoid implant prominence in this area was suggested. On the other hand, marginal distal radius fracture patterns required the plate to cross the watershed line, making conflict over plate positioning on marginal distal radius fractures. This study compared functional outcomes in patients with marginal distal radius fractures treated with two different implants.

Materials and methods

A retrospective study was conducted, all patients who received a Synthes 2.4 mm LCP or an Acumed Acu-Loc VLP between January 2015 and December 2018 were reviewed. The marginal distal radius fracture pattern was the most distal horizontal fracture line within 10 mm of the lunate fossa’s joint line. The primary outcomes including patient-reported pain scores, range of motion, and grip strength were assessed. Secondary outcomes included patient-based subjective satisfaction scores of the injured wrist and hand function. The Mayo Wrist Score and the requirement for a secondary procedure related to hardware complications were also recorded.

Results

Forty-two patients met our inclusion criteria. Twenty-one patients were treated with the Synthes 2.4 mm LCP, and 21 patients with the Acumed Acu-Loc VLP. The primary outcome revealed that post-operative range of motion (P = 0.016) and grip strengths (P = 0.014) were significantly improved in the Acu-Loc VLP group. The MAYO wrist score in the Acu-Loc VLP group was also significantly better (P = 0.006).

Conclusions

Despite advances in implant designs, flexor tendon irritation or rupture is still a complication following distal radius’s volar plating. We believe the Acumed Acu-Loc VLP design provided better functional outcomes than the Synthes 2.4 mm LCP if appropriately and carefully placed into its designed-for position. This positioning results in promising patient satisfaction when treating marginal distal radius fractures.

Pronator quadratus repair after volar plate fixation in distal radial fractures: evaluation of the clinical and functional outcome and of the protective role on the flexor tendons-a randomized controlled study

The objective was to evaluate pronator quadratus (PQ) repair following volar plating of distal radial fractures on clinical and functional outcome, as well as flexor tendon friction, during the first 12 months in ideally positioned plates (Soong 0). Confounding factors like variation in plate positioning, anatomical consolidation of the fracture and associated lesions were excluded. Eighty patients were included with distal radius fractures treated by volar locking plate in Soong grade 0 position, who were randomized to group PQ repair and group no repair. Sixty-five patients completed the 1-year follow-up: group PQ repair (n = 35) and group no repair (n = 30). Primary outcomes included range of motion, grip strength, pain level and QuickDASH. Secondary outcomes included distance between flexor pollicis longus (FPL) and volar rim and the largest distance between FPL and plate (soft tissue thickness occupied by PQ), assessed by ultrasonography. Mobility, grip strength and QuickDASH revealed no significant differences, except extension was significantly higher only in first 3 months and radial deviation was significantly higher only at 6 weeks after PQ repair. Pain level was significantly lower after PQ repair only in the first 3 months. Distance between FPL and volar rim and the largest distance between FPL and plate were significantly higher after PQ repair. No friction contact between FPL and volar rim was measured in both groups at all measurement moments. Consequently, protective flexor tendon effect of PQ repair could consequently not be concluded. In conclusion, clinical and functional short term benefits, except improved wrist extension and reduced pain in the first 3 months, were not proven in this study. In Soong grade 0, PQ repair is probably not necessary to prevent flexor tendon pathology. In Soong grade 1 or 2, this is still to be investigated. LEVEL OF EVIDENCE: 2.

Functional and radiological outcome of distal radius fractures stabilized by volar-locking plate with a minimum follow-up of 1 year

INTRODUCTION

Distal radius fractures (DRF) are the most common fractures of the upper extremities and incidence is expected to continue rising as life expectancy increases. Palmar locking plate stabilizing has since become the standard treatment for dorsally displaced DRF. Main aim of this study was to investigate correlation between radiological and clinical outcome in patients stabilized by palmar locking plate with a minimum follow-up of one year.

METHODS

A total of 524 patients with DRF, stabilized using palmar angular stable locking plate fixation were included in the study. Of these, 117 patients had to be excluded and another 177 were not accessible. The study group thus compromised 230 patients who returned for the follow-up investigation and were followed-up clinically and radiologically with a mean follow-up interval of 20 months. Outcome was evaluated using pain, range of motion (ROM) and grip strength parameters. In addition, self-assessment by patients was registered on the QuickDASH, PRWE and Mayo Score. The immediate postoperative and final checkup radiographs were scrutinized for alignment and intra-articular step-off.

RESULTS

Bivariant correlation analysis showed a significant correlation between ulnar variance and QuickDASH (r = 0.18, p = 0.01), grip strength (r = - 0.18, p = 0.04) and Mayo Score (r = - 0.23, p = 0.001). No significant differences could be found between an unacceptable (> 2 mm) and acceptable (< 2 mm) ulnar variance in respect of pain, ROM, grip strength and patient-reported outcome measurements. Age, gender, additional fracture to the ulnar styloid, or type of postoperative immobilization showed no significant or clinical important impact on the final patient-reported outcome. No significant differences in incidence of complications, ROM or loss of reduction could be found in any patients over or under 65 years of age.

CONCLUSIONS

Stabilization of DRF by palmar angular stable locking plate is a safe form of treatment and results in a good clinical and radiological outcome with low complication rate. Ulnar variance showed a significant correlation to grip strength, QuickDASH and Mayo Score, but an unacceptable ulnar variance (> 2 mm) was not associated with a worse clinical important outcome. Age (< 65/> 65 years), gender and type of immobilization had no impact on the complication rate or in the final functional or radiological outcome.

Indications, surgical approach, reduction, and stabilization techniques of distal radius fractures

Distal Radius fractures (DRF) are one of the most common injuries in the upper extremity and incidence is expected to rise due to a growing elderly population. The complex decision to treat patients operatively or conservatively depends on a large variety of parameters which have to be considered. No unanimous consensus has been reached yet, which operative approach and fixation technique would produce the best postoperative functional results with lowest complication rates. This article addresses the available evidence for indications, approaches, reduction, and fixation techniques in treating DRF.

Salvage procedure after malunited distal radius fractures and management of pain and stiffness

Indications for surgical treatment of distal radius fractures (DRF) remain controversial in the literature, especially in elderly patients. Complication rates after operatively treated DRF are low and well documented. These include malunion, degenerative osteoarthritis in the radiocarpal joint and subsequently pain and impaired hand function. If conservative treatment fails then salvage procedures are necessary. This review summarizes the therapeutic options available to treat degenerative osteoarthritis after malunited distal radius fractures, regardless of the initial operative or conservative treatment.

Complications after operatively treated distal radius fractures

In the recent years, treatment of distal radius fractures (DRF) has advanced considerably. Surgical fixation with palmar angular stable plate has gained popularity, due to a reported lower complication rate when compared to dorsal fixation. The type of trauma or injury, surgical procedure and impaired bone quality are all contributors to complications in DRF. The main aim of this review is to summarize the most common complications and possible therapeutic solutions. In addition, strategies for minimizing these complications will be discussed.

Rehabilitation after distal radius fractures: is there a need for immobilization and physiotherapy?

Although the literature generally agrees that displaced distal radius fractures require surgery, no single consensus exists concerning the length of immobilization and type of post-operative physiotherapeutic rehabilitation program. Palmar locking plate fixation represents a very stable fixation of the distal radius, and was assessed biomechanically in various studies. Surprisingly, most authors report additional immobilization after plate fixation. One reason might be due to the pain caused during active wrist mobilization in the early post-operative stages or secondly to protect the osteosynthesis in the early healing stages preventing secondary loss of reduction. This article addresses the biomechanical principles, current available evidence for early mobilization/immobilization and impact of physiotherapy after operatively treated distal radius fractures.

Biomechanical considerations on a CT-based treatment-oriented classification in radius fractures

A wide range of different classifications exist for distal radius fractures (DRF). Most of them are based on plane X-rays and do not give us any information on how to treat these fractures. A biomechanical understanding of the mechanical forces underlying each fracture type is important to treat each injury specifically and ensure the optimal choice for stabilization. The main cause of DRFs are forces acting on the carpus and the radius as well as the position of the wrist in relation to the radius. Reconstructing the mechanism of the injury gives insight into which structures are involved, such as ruptured ligaments, bone fragments as well as the dislocated osteoligamentous units. This article attempts to define certain key fragments, which seem crucial to reduce and stabilize each type of DRF. Once the definition is established, an ideal implant can be selected to sufficiently maintain reduction of these key fragments. Additionally, the perfect approach is selected. By applying the following principles, the surgeon may be assisted in choosing the ideal form of treatment approach and implant selection.

Ulnar shortening osteotomy as a treatment of symptomatic ulnar impaction syndrome after malunited distal radius fractures

A malunited distal radius fracture can lead to symptomatic ulnar impaction syndrome, which is a common cause for ulnar-sided wrist pain. If conservative treatment fails and symptoms persist after an arthroscopic ulnocarpal debridement, ulnar shortening osteotomy (USO) is the treatment of choice. Since the first USO described by Milch in 1941 after a malunited Colles fracture, many techniques have been described varying in surgical approach, type of osteotomy and osteosynthesis material used. Many studies demonstrated good to very good functional results after USO, reporting, however, a delayed union or non-union rate up to 18%. A modern, low profile, locking plate showed in our short-term study very good functional results and no implant-associated complications, in particular no non-union.

Volar plate for intra-articular distal radius fracture. A prospective comparative study between elderly and young patients

INTRODUCTION

Treatment of the distal radius fracture in elderly remains controversial. The objective was to assess the outcomes of volar locking plate for displaced complete intra-articular distal radius fractures in elderly as compared to younger patients.

HYPOTHESIS

The outcomes in elderly patients would be comparable with those in younger patients with a low rate of complications.

MATERIAL AND METHODS

Non-randomised prospective comparative study between 70 patients older than 65 years and 46 younger patients with AO type-C fractures. The main outcome was Disabilities Arm, Shoulder and Hand (DASH) score. Secondary variables were Patient-Rated Wrist Evaluation (PRWE) score, range of motion, Visual Analogue Scale (VAS) for pain, and grip strength. Radiological measurements were also performed.

RESULTS

The mean follow-up was 30.9 (range, 24-53) months. There were no significant differences in mean DASH, PRWE, VAS-pain, wrist motion or radiological parameters at final follow-up. Multivariate analysis showed that the functional outcomes were significantly influenced by baseline ulnar positivity greater than 3mm at baseline but not by age.

DISCUSSION

The study hypothesis was confirmed. Surgical treatment with volar locking plate for displaced complete intra-articular fractures of the distal radius in elderly patients represents a safe and effective treatment alternative with similar early complication rate than in younger.

LEVEL OF EVIDENCE

III, cohort study.

[Palmar radioscapholunate arthrodesis with distal scaphoidectomy]

OBJECTIVE

Radioscapholunate (RSL) arthrodesis with distal scaphoidectomy using an angular stable plate and palmar access in post-traumatic or degenerative osteoarthritis limited to the radiocarpal joint.

INDICATIONS

Osteoarthritis limited to the radiocarpal joint with intact mediocarpal joint after malunited intra-articular distal radius fractures, rheumatoid osteoarthritis, scapholunate advanced collapse (SLAC) up to stage II.

CONTRAINDICATIONS

Mediocarpal osteoarthritis, poor patient compliance, SLAC from stage III, osteitis.

SURGICAL TECHNIQUE

The palmar RSL arthrodesis is performed using the palmar approach between the flexor carpi radialis tendon and the radial artery. After releasing the pronator quadratus muscle, a longitudinal capsulotomy is performed and the radiocarpal joint is inspected. After correction of a volar or dorsal intercalated segmental instability of the lunate, the lunate is temporarily fixed to the scaphoid using a K-wire. The distal quarter of the scaphoid and the palmar rim of the distal radius is resected and the cartilage between the scaphoid, lunate and distal radius is removed. The scaphoid and lunate are temporarily fixed to the distal radius using K‑wires. Under image intensifier control the angular stable low-profile plate (e.g., volar 2.5 Trilock RSL Fusion plate [Medartis® Aptus® Basel, Switzerland]) is fixed to the distal radius in the long-leg hole. The scaphoid and lunate are fixed distally with two screws each. The carpus is pushed distally using a Codeman distractor and the cancellous bone graft is impacted. Finally, the shaft is fixed with angular stable screws.

POSTOPERATIVE MANAGEMENT

Immobilization using a plaster cast or thermoplastic short-arm orthosis for 5 weeks. After 2 weeks, the orthosis can be removed during hand therapy with active wrist and finger exercises. Normal activities permitted after 12 weeks.

RESULTS

Palmar RSL arthrodesis and distal scaphoidectomy using angular stable plate fixation shows a high union rate and pain relief while maintaining good residual mobility of the wrist.

Positioning of a Volar Locking Plate with a Central Flexor Pollicis Longus Tendon Notch in Distal Radius Fractures

Background  Volar locking plates with a central notch were designed to reduce the risk of flexor pollicis longus (FPL) tendon irritation after volar plating for distal radius fractures. Objective  The purpose of this study was to evaluate the course of the FPL tendon after FPL-plate osteosynthesis to identify a plate position that avoids an impingement with the FPL tendon. Patients and Methods  Nineteen patients treated with volar plating using an FPL plate for a distal radius fracture were evaluated. Transverse ultrasound images were used to assess whether the profile of the FPL tendon lied within the plate notch. The position of the FPL tendon on transverse ultrasound images was transferred onto postoperative dorsovolar X-ray images to define an FPL tendon corridor for a plate position not interfering with the FPL tendon. Results  The FPL tendon was aligned inside the plate notch completely in three cases, partially in 11 cases, and missed the notch in five cases. An FPL corridor was defined at the level of the watershed line with all FPL tendons being completely (74%) or partially (26%) aligned inside that corridor. There was a moderate correlation between the plate notch being positioned inside this corridor and the FPL tendon being positioned inside the plate notch ( r  = 0.49; p  = 0.033). Conclusion  It seems advantageous to place the plate notch within a corridor parallel to the radial shaft between the ulnar edge of the scaphoid tubercle and the scapholunate interval for the FPL tendon protection. Level of Evidence  This is Level IV study.

Volar locking plates not touching the flexor pollicis longus tendon appear as prominences on radiographs: a cadaver study

Background

Plate protrusion is a risk factor for flexor pollicis longus (FPL) rupture following volar locking plate (VLP) surgery. However, plate prominence on follow-up radiographs is common. We hypothesised that a VLP that does not touch the FPL tendon can appear as a plate prominence projected over the volar ridge on lateral radiographs.

Materials and methods

We studied six current designs of widely used plates in formalin-fixed cadavers. Each plate was placed in six cadavers. We analysed 36 different plate–cadaver combinations. The main aim of plate fixation was to position the plate in the most distal position without FPL tendon contact. Radiographs were obtained using fluoroscopy. We evaluated plate prominence from the volar ridge according to the Soong grading system.

Results

Soong grades 0 (plate did not extend beyond volar ridge), 1 (plate protruded beyond volar ridge) and 2 (plate directly on or located beyond the volar ridge) were observed in 23 (63.9%), 9 (25.0%) and 4 (11.1%) cadavers, respectively. VariAx, DVR and VALCP showed grade 1 prominence, whereas Acu-Loc2, HYBRIX and MODE showed grade 2 prominence.

Conclusions

Implant protrusion was observed in 36% of plate–cadaver combinations, even if the plate did not touch the FPL. Estimating the risk of FPL rupture using lateral radiographs alone is likely insufficient. Our findings can be applied to accurately identify the presence of implant prominence following VLP surgery.