Selection of tendon grafts for distal radioulnar ligament reconstruction and report of a modified technique

Prediction Of Palmaris Longus Tendon Length And Thickness Through Simple Anthropometric Measurements

OBJECTIVE

This study aimed to test whether palmaris longus tendon (PLT) length and thickness can be predicted from simple anthropometric measurements.

MATERIALS AND METHODS

120 healthy volunteers with bilateral PL muscles were enrolled in this prospective study. PLT length and thickness were measured by ultrasonographic examination. Anthropometric measurements included body height, weight, forearm length, and wrist circumference. Correlation, linear regression, and Bland-Altman plot were used for analysis.

RESULTS

The mean PLT length and thickness were 10.8±1.4 cm and 4.0±0.9 mm, respectively. Body height and PLT length had a moderate positive correlation (r:0.407, p:0.001), and forearm length and PLT thickness had a weak positive correlation (r:0.229, p:0.001). The regression analysis showed that body height was the best predictor for PLT length, and forearm length was the best predictor for PLT thickness. The regression equations were as follows: PLT length=0.276+(0.062×height) (r2=0.165, p<0.001) and PLT thickness=1.373+(0.108×forearm length) (r2=0.052, p<0.001). The predicted PLT lengths and thicknesses were calculated using these regression formulas and compared with the actual thicknesses and lengths using the Bland-Altman plot. The upper and lower limits of agreement (95% CI) ranged from -2.54 cm to 2.51 cm for actual PLT length and predicted PLT length and from -1.76 mm to 1.74 mm for actual PLT thickness and predicted PLT thickness in the Bland-Altman plot with a weak agreement and proportional bias.

CONCLUSIONS

These findings indicate that height and forearm length have limited accuracy in predicting PLT length and thickness. The preoperative ultrasonographic examination can provide valuable assistance, particularly in cases that require grafts with precise length and thickness requirements.

Biomechanical Comparison of Distal Radioulnar Joint Reconstruction Graft Preparation Techniques

Background  Graft preparation techniques for the Adams-Berger distal radioulnar joint (DRUJ) reconstruction vary among surgeons with insufficient evidence to support any specific technique. Questions/Purposes  We compared survival with cyclic loading, absolute elongation, elongation rate, and modes of failure of four graft preparation techniques. Methods  Fifteen porcine extensor tendons were divided into three equal groups: tendon only; tendon augmented along its full length with nonlocking 2-0 FiberLoop suture spaced at 6 mm intervals; and tendon with suture at 12 mm intervals. Suture only was also tested. Samples were woven through custom radius- and ulna-simulating jigs mounted on a mechanical testing machine. Samples underwent a staircase cyclic loading protocol and were then inspected visually for the mode of failure. Survival with cyclic loading, absolute elongation, and elongation rate was compared. Results  Average survival with cyclic loading of suture-augmented tendon was significantly higher than tendon only. All tendon groups had significantly higher survival compared with suture only. Absolute elongation was subject to variability due to initial nonlinear elongation behavior of samples. The elongation rate was significantly lower with suture compared with all tendon groups. Modes of failure included rupture of the tendon and/or suture at the simulated graft-bone interface and elongation of the entire construct without rupture. Conclusions  In this biomechanical study, augmentation of porcine tendons with suture spaced at either 6 or 12 mm for DRUJ reconstruction significantly increased survival to a staircase cyclic loading protocol Clinical Relevance  For the Adams-Berger reconstruction, tendon grafts augmented along their entire length by nonabsorbable braided suture are biomechanically superior to tendon alone.

Ligament reconstruction with modified suture anchor fixation technique for chronic distal radioulnar joint instability: A case report and literature review

INTRODUCTION

The chronic instability of the DRUJ should be appropriately treated. Ligament reconstruction in the original technique needs an adequate length of the graft, which needs to be modified in such a case.

CASE PRESENTATION

A 27-year-old male presented with right wrist pain accompanied by limited movement that has been felt for the last two months. There was an obvious deformity with tenderness. Palpation revealed a positive ballottement and piano-key sign test. An X-ray examination revealed a union fracture one-third distally on the right radius bone with dorsal dislocation of the right distal radioulnar joint. The result of an MRI confirmed a triangular fibrocartilage complex tear. The patient was diagnosed with chronic DRUJ instability.

DISCUSSION

We performed a chronic DRUJ reconstruction using the harvesting palmaris longus tendon. However, the length of the graft is too short. Further, we performed a modified technique with suture anchor fixation for this patient. This technique could be a helpful alternative if the length of the graft is insufficient. As a result, there was an improvement in the DASH score and EQ5D questionnaires.

CONCLUSION

Chronic DRUJ instability could be treated by ligament reconstruction with modified suture anchors fixation in the inadequate length of the graft situation.

Anomalous Extensor Indicis Proprius Muscle Extending Beyond the Extensor Retinaculum: A Case Report

CASE

During dissection of the upper limb of a cadaver in preparation for a first-year anatomy course, an extensor indicis proprius (EIP) variant was discovered with its muscle belly extending distal to the extensor retinaculum and beyond what has been previously described in the literature.

CONCLUSION

EIP is commonly used as a tendon transfer for extensor pollicis longus rupture. Few anatomic variants of EIP have been reported in the literature, but such variants should be considered because of their consequences to the success of tendon transfer and potential implications for diagnosis of an otherwise unexplained mass of the wrist.

Biomechanical evaluation of interference screw fixation techniques for distal radioulnar ligament reconstruction: a cadaveric experimental study

INTRODUCTION

In the reconstruction of distal radioulnar ligaments (DRULs), interference screws can be used for antegrade or retrograde fixation of grafts to the ulna. However, the biomechanics of interference screw fixation are currently unknown. This study aimed to determine the biomechanical effects of these two fixations on the distal radioulnar joint (DRUJ) in a cadaveric model and to investigate the appropriate initial tension.

MATERIALS AND METHODS

A total of 30 human cadaver upper extremities were used, and the DRULs were reconstructed according to Adams' procedure. First, eight specimens were randomly divided into two groups: antegrade and retrograde, followed by translational testing and load testing. Then, the other eight specimens were divided into the two groups above, and the contact mechanics, including forces, areas, and pressures, were measured. Finally, to investigate the appropriate initial tension, the remaining 14 specimens were fixed with interference screws under different tensions in an antegrade way, and the translational testing was repeated as before.

RESULTS

In the neutral position, antegrade fixation exhibited less translation than retrograde fixation (7.21 ± 0.17 mm versus 10.77 ± 1.68 mm, respectively). The maximum failure load was 70.45 ± 6.20 N in antegrade fixation, while that in retrograde fixation was 35.17 ± 2.95 N (P < 0.0001). Antegrade fixation exhibited a larger increase in contact force than retrograde fixation (99.72% ± 23.88% versus 28.18% ± 10.43%) (P = 0.001). The relationship between tension and displacement was nonlinear (Y = - 1.877 ln(x) + 7.94, R² = 0.868, P < 0.0001).

CONCLUSIONS

Compared with retrograde fixation, the antegrade fixation of interference screws may be a more reliable surgical technique, as it shows a higher failure load and stability. In addition, to avoid the risk of potential arthritis caused by anterograde fixation, we propose an equation to determine the appropriate initial tension in DRUL reconstruction.

Biomechanical Evaluation of Distal Radioulnar Joint Instability and Adams Procedure

PURPOSE

Distal radioulnar joint (DRUJ) instability may occur after an injury, resulting in pain and reduced strength. When primary repair is not possible or initial fixation has failed, chronic instability may result, requiring a reconstructive procedure such as the Adams procedure. The first purpose of this study was to evaluate the role of the triangular fibrocartilage complex and various components of the interosseous membrane as they were sectioned. The second purpose was to evaluate the Adams procedure in stabilizing the forearm.

METHODS

Eight fresh cadaver forearms were dynamically moved through an average range of 56.8° pronation to 54.8° supination and tested first with the forearm intact and then after sectioning each of the following structures: the dorsal (DRUL) and palmar radioulnar ligaments (PRUL), the distal interosseous membrane, and the central band. Finally, they were tested after reconstruction using the Adams procedure. During each forearm motion and provocative shuck, the motion of the radius and ulna were measured and the locations of the radial attachments of the DRUL, PRUL, and sigmoid notch and ulnar fovea were computed.

RESULTS

Significant increases in the gap between the ulnar fovea and the attachment sites of the DRUL and PRUL were observed with incremental sectioning, most notably after sectioning of the central band. Reconstruction significantly reduced the gap at the DRUL and PRUL sites during dynamic motion.

CONCLUSIONS

This study reinforces the concept that DRUJ stability depends on more than the radioulnar ligaments, ulnocarpal ligaments, and triangular fibrocartilage complex, but is also significantly affected by the distal and central interosseous membrane. Reconstruction reduces gapping.

CLINICAL RELEVANCE

These results suggest that the Adams reconstruction is a reasonable option to address DRUJ instability but may be an incomplete solution in the setting of a ruptured interosseous ligament.

Morphometric analysis and surgical adequacy of palmaris longus as a tendon graft. A systematic review of cadaveric studies

INTRODUCTION

The tendon of the palmaris longus is commonly used as a tendon graft in many reconstructive surgeries. Easy to access and at proximity to the hand, the palmaris longus tendon is considered as the optimal tendon source for hand reconstructive surgery. However, and besides its inconsistency, the size of the palmaris longus tendon is reported to show variability. The aim of this study is to look for the surgical adequacy of the palmaris longus tendon by conducting a quantitative synthesis on its length and width in human populations and its correlation with the forearm length.

METHODS

Twenty-four studies met the inclusion criteria including 1761 cadaveric limbs.

RESULTS

The results were as following: (a) the mean palmaris longus tendon length was of 13.9 ± 2.6 cm, (b) the mean ratio palmaris longus tendon length/forearm length was of 0.545 ± 0.06, (c) the weighted correlation value was of 0.686, and (d) the mean palmaris longus tendon width was of 4.0 ± 1.7 mm. Only five studies reported a palmaris longus tendon length of more than 15 cm. The palmaris longus tendon length was shown to vary between ancestries; the Japanese had the shortest while Malaysian the longest palmaris longus tendons. All studies but one reported a palmaris longus tendon mean width of more than 3 mm where the minimal mean palmaris longus tendon width was of 2.5 mm.

CONCLUSION

While the requested length depends on the recipient site and/or type of reconstructive surgery, the palmaris longus tendon often met the required diameter for grafting. Our review demonstrated that while palmaris longus length varies between ancestries, its width is often adequate for grafting. In addition, the forearm length could be a good predictor of palmaris longus tendon length; such correlation could assist surgeons when planning to use palmaris longus tendon as a graft source.

Predicting Tendon Tissue Grafting Source From the Extensors of Long Fingers: A Systematic Review of Cadaveric Studies

Background: The use of tendon tissue for transfer and grafting is a common practice in hand surgery. Many local tendons are usually used, mainly that of the palmaris longus muscle. However, this tendon could be absent in up to 46%. Extra slips of the extensor digitorum communis (EDC) and extra tendons such as the extensor indicis (EI) and the extensor digiti minimi (EDM) could be valuable sources for tendon tissue. Methods: A systematic review was conducted to quantify the proportion of extra slips in relation to each tendon and extra tendons in relation to each long finger. The aim is to better predict the location of tendon tissue sources on the dorsum of the hand in reconstructive surgery. Results: Based on 39 studies including 7847 hands, the cumulative frequencies of extra slips and extra tendons and the association between double-slip frequency and ancestry were as follows: (1) the little finger showed the highest cumulative frequency of extra slips (96.54%), followed by the ring (37.5%), long (30.6%), and index (9.5%) fingers; (2) the index with its EI and its variants and the little finger with its EDM bear by far the highest cumulative frequency of extra tendons (≈100%); and (3) double slips are found to be rare in Indian populations, most prevalent in Japanese populations, more prevalent in the index and little fingers of Caucasians, and more prevalent in the ring fingers of Middle Eastern populations. Conclusions: Knowledge of the frequencies of extra slips for each long extensor tendon and extra tendons for each long finger along with their prevalence in different populations would improve: (1) location prevision of tendon source for tendon grafting; and (2) surgical planning while supporting a patient-centered approach. Evidence-based hand anatomy would have a major potential to contribute to the practice of an evidence-based hand surgery. Predicting the possible tendon sources that could be present on the dorsum of the hand is thought to be very valuable for hand surgeons. In addition and from an evolutionary perspective, we hypothesized that the observed significantly higher frequency values of the double-slip and triple-slip types of the EDC of the ring finger, EDC of the little finger, and EDM might indicate a natural selection tendency for a higher independence of the former digits in the future evolution of the human hand.

Ultrasound determination of presence, length and diameter of the palmaris longus tendon

Inadvertent median nerve harvest is a devastating complication of palmaris longus harvest. Accurate assessment of palmaris longus presence and dimensions preoperatively would minimize this risk and assure safe harvest. We hypothesized that ultrasound would accurately predict palmaris longus presence, length and diameter. Seventeen cadaveric forearms were studied using a LOGIQ-E9 ultrasound. Two radiologists assessed palmaris longus presence and dimensions. Each wrist was explored, and the tendon was harvested and measured. Inter-rater reliability and agreement between measurements was assessed. The palmaris longus was present in 13 of 17 forearms. Both radiologists correctly identified the tendon and its absence (sensitivity and specificity, 100%). Ultrasound assessment of palmaris longus dimensions significantly correlated with surgical measurements. Intraclass correlation coefficient between radiologists was 0.97. We conclude that ultrasound can determine palmaris longus presence and dimensions with excellent accuracy and inter-observer reliability. Ultrasound is useful for preoperative evaluation of the palmaris longus and its use will increase patient safety.