Radial nerve in the radial tunnel: anatomic sites of entrapment neuropathy

Common anatomical structures that can lead to radial nerve entrapment in the radial tunnel (radial tunnel syndrome) were studied in 46 embalmed cadaveric upper limbs. After dissecting the radial tunnel, we investigated: the radial nerve and its division into superficial and deep (DBRN) branches; the course of the DBRN in relation to the extensor carpi radialis brevis (ECRB) muscle; the presence of fat; fibrous adhesions between the anterior radiohumeral joint capsule and the DBRN; the nature of the superomedial margin of the ECRB; vascular arcades of the radial recurrent vessels; and the superior and inferior borders of the superficial layer of the supinator muscle. The locations of some of these structures were measured in reference to two fixed points: the radiohumeral joint line and a line joining the tips of medial and lateral epicondyles of humerus. Near the radiohumeral joint, fibrous adhesions were observed between the DBRN and underlying capsule in 23/46 (50%) cases; vascular arcades of the radial recurrent vessels were found in 33/46 (72%) cases; the superomedial margin of the ECRB was tendinous in 36/46 (78%) instances; the superior border of the superficial layer of the supinator muscle was noted to be tendinous (arcade of Frohse) in 40/46 (87%) specimens, and the inferior border of the superficial layer of the supinator muscle was tendinous in 30/46 (65%) cases. These anatomical features in the radial tunnel are significant enough to lead to entrapment neuropathy of the radial nerve.     

Can palmar creases serve as landmarks for the deeper neuro-vascular structures?

Purpose

The aim of this study was the examination of the superficial anatomy of palmar creases and their relation to deeper neuro-vascular structures.

Methods

Four creases: distal wrist flexion crease, thenar crease, proximal palmar crease and distal palmar crease were evaluated with reference to the following structures: palmar cutaneous branch of median nerve, palmar cutaneous branch of ulnar nerve, the nerve of Henle, transverse palmar branches from ulnar nerve, recurrent motor branch of median nerve, radial proper palmar digital nerve to the index and the ulnar proper palmar digital nerve to the thumb, Berrettini’s communicating branch, ulnar nerve and artery, superficial palmar arch. We performed dissections of 20 cadaveric upper limbs derived from a homogenous Caucasian group. In our study we measured the location of surgically important structures with reference to palmar skin creases.

Results

Among the other observations we noticed that the palmar cutaneous branches of the median and ulnar nerves were located at least 0.5 cm away from the thenar crease. The superficial palmar arch was found between the thenar and proximal palmar crease and never crossed the proximal or distal palmar creases.

Conclusions

These anatomical dissections will provide reference material for further ultrasound studies on the arrangements of neuro-vascular structures in reference to superficial palmar creases.     

Anatomic bases for the compression and neurolysis of the deep branch of the radial nerve in the radial tunnel

The anatomy of the radial tunnel was studied on twenty-five elbow preparations. We noted five different elements that could affect the deep branch of the radial nerve in the radial tunnel and cause an entrapment syndrome: a capsule-tendon-aponeurotic complex on the anterior aspect of both the humeroradial joint and the radial head, the vascular arcade formed by the radial recurrent a. and its branches, the arcade formed by the medial edge of extensor carpi radialis brevis muscle, and the superior and inferior arcades of the superficial layer of the supinator muscle. These results are compared with recent anatomical and clinical data, and the relevance of a surgical approach between the extensor carpi radialis brevis and longus muscles is discussed.     

Inhomogeneous architectural changes of the quadriceps femoris induced by resistance training

Purpose

This study aimed to clarify whether resistance training-induced changes in muscle architecture are homogeneous among the quadriceps and over different regions within each muscle.

Methods

Eleven recreationally active men (27 ± 2 years) completed a 12-week resistance training program for knee extensors. Before and after the intervention, muscle thicknesses, fascicle lengths, and pennation angles of the four muscles (vastus lateralis, vastus medialis, vastus intermedius, rectus femoris) in several regions (2–4 regions per each muscle) were measured using ultrasonography. Anatomical cross-sectional areas (ACSAs) at the same positions as the ultrasound measurements were determined from magnetic resonance images.

Results

Relative increases in the ACSA, muscle thickness, and pennation angle of the rectus femoris were significantly greater than those of the vasti. Relative increases in the ACSAs of the vastus lateralis and rectus femoris were significantly greater in the distal than in the proximal region, and those in the muscle thickness and pennation angle of the vastus intermedius were significantly greater in the medial than in the lateral region. Fascicle lengths did not change in any muscles. The interrelations between muscle thickness and pennation angle remained unchanged after the intervention, with a significant association between the relative changes of the two variables.

Conclusion

The current results indicate that (1) hypertrophy of the quadriceps femoris is associated with a proportional increase in pennation angle but not necessarily in fascicle length, and (2) training-induced changes in muscle size and pennation do not evenly occur among the quadriceps, along or across a muscle.     

骨间后神经受压的解剖学基础

目的阐明骨间后神经(PIN)卡压的原因及其手术治疗提供解剖基础。方法30侧尸体上肢标本,将PIN分为3段(即桡管段、旋后肌管段和旋后肌管后段)观察其肌支的分支情况;用卡尺对桡管(RT)、旋后肌管(ST)和桡侧腕短伸肌腱弓(AECRM)的形态和大小进行了观测,并对ST入口和出口的体表投影定位。结果ST入口和出口的宽度分别为(14.1±2.1)mm和(6.2±1.7)mm,长度为(35.0±6.9)mm。PIN从桡骨头至旋后肌腱弓(AF)和PIN从旋后肌穿出处的长度分别为(19.3±4.4)mm和(53.4±5.2)mm。AF的53.3%由肌性加腱性组织构成,23.3%由腱性组织构成,23.3%由肌组织构成。70%旋后肌远侧缘由腱性组织构成,所有AECRM均是腱性。桡骨背侧桡骨头下方1示指宽和3示指宽分别为ST的入口和出口的体表投影。结论本文提供的RT、ST和AECRM详细形态资料,对于PIN卡压的诊断和手术治疗具有指导意义。     

桡神经深支卡压综合征的解剖学研究

根据５４侧成人尸体肘部桡管，旋后肌管及桡神经深支在肘部行程的解剖学研究，特别观察到桡侧腕短伸肌纤维桥有９０．６％为全腱性，其中有８８．９％与旋后肌弓外侧半重叠直接紧邻桡神经深支，认为该纤维桥是桡神经深支在肘部卡压的主要因素。并注意到桡神经深支与桡骨头部位的关节囊等关系密切，提示临床医生注意。     

骨间后神经穿桡管远端处的解剖特点及其临床意义

目的：了解骨间后神经穿旋后肌后可能的卡压位置及临床意义,方法：在2倍放大镜下解剖骨间后神经穿旋后肌后的行程,分支,可能卡压位置以及前臂活动对其影响。结果：骨间后神经穿旋后肌后恒定地分尺仙支和桡侧支;旋后肌远侧缘和拇短伸肌,拇长展肌浅面的腱性肌纤维结构可能是致卡压的解剖结构,前臂伸肌群的活动可 诱发上述结构卡压骨间后神经,结论：在桡管远端同样存在卡坟骨间后神经的解剖结构,必要时应手术探查,松解。     

The arcade of Fröhse : an anatomic study

Summary An anatomic study of the appearance and consistency of the upper arcade of the superficial layer of the supinator m. was carried out on 106 elbow-joint dissections. A classification of the structure was drawn up in order to discern the criteria for normality. An arcade of a tendinous nature (arcade of Fröhse) was encountered in the majority of cases (64.1%). At first sight, it could not be ascribed a compressive role affecting the posterior branch of the radial n. Macroscopic examination of the nerve prior to its entry under the supinator arcade revealed the presence of macroscopic lesions in 42.9% of cases. This high incidence does not permit any conclusions regarding the pathologic significance of this type of lesion.

---

L'arcade de Fröhse: étude anatomique

Résumé Une étude anatomique de l'aspect et de la consistance de l'arcade supérieure du faisceau superficiel du m. supinateur a été réalisée sur 106 préparations de coudes. Une classification basée sur la structure a été établie afin de dégager des critères de normalité. Une arcade tendineuse (arcade de Fröhse) est rencontrée dans la majorité des cas (64.1%). On ne peut lui attribuer à priori un rôle de compression du rameau profond du n. radial. L'observation macroscopique du nerf avant son passage sous l'arcade du m. supinateur révèle la présence d'altérations macroscopiques dans 42.9% des cas. Cette incidence élevée ne nous permet pas de conclure à la signification pathologique de ce type d'altération.

     

Arterial supply of the distal humerus

Purpose

Distal humeral fractures are rare, but severe injuries, the treatment of which is often accompanied by serious complications and its outcome strongly depends on the quality of surgical therapy. Non-union is a common entity, compromising clinical results and requiring revision surgery. Osteonecrosis is an underestimated etiologic factor in the development of non-union. The present study aims to display the distribution patterns of the arterial vessels at the distal humerus, to correlate the displayed vessels with local nutrient foramina and to disclose an endangerment of these structures by common osteosynthetic implants.

Methods

Eight plastinated fresh frozen upper extremities were digitally analyzed regarding the vascular density of the cancellous bone, by calculating the ratio of area comprised by arterial vessels and the area comprised by cancellous bone on sagittal cuts of the distal humerus. Possible differences in the vascular density of the medial epicondylar region, the lateral epicondylar region and a watershed area between the epicondyles and distal to the supracondylar region were investigated. On the basis of 200 macerated humeri, the distribution pattern of cortical nutrient foramina and their anatomic relation to properly applied common distal humerus plates were documented.

Results

The data show a significantly higher density of vessels per cancellous bone in the epicondylar regions than in the watershed region (p < 0.000, median 0.148 vs. 0.103). The analysis of the nutrient foramina showed distinct distribution patterns with a single foramen over the medial epicondyle (55 specimens, 27.5 %) and an area of several foramina at the posterior part of the lateral epicondyle (200 of the specimens, 100 %). In almost every specimen, the application of the osteosynthetic implants led to an overlay over the investigated nutrient foramina.

Discussion

Osteonecrosis and non-union are severe complications in the surgical treatment of distal humeral fractures. The biology of the bone, especially the blood supply, has to be respected as much as possible during open procedures, to optimize bony healing. This has to be considered when performing periosteal stripping or applying osteosynthetic plates over the postero-lateral and medial epicondyle. The watershed area of the distal humerus has to be considered as being prone to minor arterial blood supply and thereby non-union is possible, if the arterial vessels coming from the epicondyles are destroyed.     

Effects of isometric training on the knee extensor moment–angle relationship and vastus lateralis muscle architecture

Purpose

To analyse the muscle adaptations induced by two protocols of isometric training performed at different muscle lengths.

Methods

Twenty-eight subjects were divided into three groups: one (K90) performed isometric training of the knee extensors at long muscle lengths (90° of knee flexion) for 8 weeks, and the second group (K50) at short muscle lengths (50°). The subjects of the third group acted as controls. Isokinetic dynamometry was utilized to analyse the net moment–angle relationship and vastus lateralis muscle thickness at three different locations, and pennation angles and fascicle length at 50 % of thigh length were measured at rest with ultrasonography.

Results

Only subjects from K90 group showed significant increases in isokinetic strength (23.5 %, P < 0.001), while K50 group showed no increases in isokinetic strength: (10 %, P > 0.05). There was a shift in the angle of peak torque of the K90 group to longer muscle lengths (+14.6 %, P = 0.002) with greater increases in isokinetic strength, while the K50 angle shifted to shorter muscle lengths (?7.3 %, P = 0.039). Both training groups showed significant increases in muscle thickness, (K90 9–14 % vs. K50 5–9 %) but only K90 significantly increased their pennation angles (11.7 %, P = 0.038). Fascicle lengths remained unchanged.

Conclusions

Isometric training at specific knee angles led to significant shifts of peak torque in the direction of the training muscle lengths. The greater strength gains and the architectural changes with training at long muscle lengths probably come from a combination of different factors, such as the different mechanical stresses placed upon the muscle–tendon complex.     

Intermuscular aponeuroses between the flexor muscles of the forearm and their relationships with the ulnar nerve

Introduction

The aim of this study was to clarify the morphological characteristics of the intermuscular aponeurosis between the flexor carpi ulnaris (FCU) and flexor digitorum superficialis (FDS; IMAS), and that between the FCU and flexor digitorum profundus (FDP; IMAP), and their topographic relationships with the ulnar nerve.

Materials and methods

Fifty limbs of 38 adult cadavers were studied.

Results

The IMAS extended along the deep surface of the FCU adjoining the FDS, having the appearance of a ladder, giving off “steps” that decreased in width from superficial to deep around the middle of the forearm. Its proximal part divided into two bands connected by a thin membrane, and was attached to the medial epicondyle and the tubercle (the most medial prominent part of the coronoid process of the ulna), respectively. The IMAP extended deep between the FCU and FDP from the antebrachial fascia, and its distal end was located on the posterior border of the FCU. The IMAP became broader toward its proximal part, and its proximal end was attached anterior and posterior to the tubercle and the olecranon, respectively. The ulnar nerve passed posterior to the medial epicondyle and then medial to the tubercle, and was crossed by the deep border of the IMAS at 58.3 ± 14.1 mm below the medial epicondyle.

Conclusion

The deep border of the IMAS and aberrant tendinous structure passing across the ulnar nerve, or the parts of the IMAS and IMAP passing posterior to the ulnar nerve are potential causes of ulnar nerve compression.

     

Proximal ulna morphometry: which are the “true” anatomical preshaped olecranon plates?

Purpose

To define the optimum design of the anatomical preshaped olecranon plate.

Methods

The geometry of the proximal ulna was studied in 200 paired Caucasian ulnae, using a digital caliper and goniometer. Gender and side differences were analyzed. Results were compared with the corresponding geometrical parameters of three olecranon plates with different contour. All three plates were placed on the dorsal surface of a “model” ulna, i.e., a right dried ulna having osteometric parameters similar to the averages of our sample, and plate-to-bone fit was examined in two planes.

Results

The proximal ulna had an 8.48° (2.1°–15.7°) mean varus angulation and an 8.49° (1.70°–14.10°) mean anterior angulation, located on average 8.19 cm (5.68–11.66 cm) and 8.63 cm (5.28–11.92 cm) distal to the bone’s most proximal point, respectively. The mean olecranon angle was 110.34° (98.70°–125.80°) and the olecranon length was 1.58 cm on average (1.20–2.12 cm). Only the plate having both varus and anterior angulation presented a good plate-to-bone fit in both planes.

Conclusions

A “true” anatomical preshaped olecranon plate should have both varus and anterior angulation close to the average angulations of the normal ulna and located in a certain distance from its proximal edge. The olecranon part of the plate should primarily not exceed the olecranon length and secondarily be close to the average olecranon angle. We believe that such a plate may facilitate intraoperative restoration of the proximal ulna complex anatomy, when dealing with comminuted or Monteggia fractures, thus leading to better postoperative results.     

Anatomic and morphometric study of the arcade of Frohse in cadavers

The most superior part of the superficial layer of the supinator muscle is named as the arcade of Frohse (AF). The deep branch of the radial nerve runs under this arch. The AF is reported to be the most common structure causing entrapment neuropathy of the deep branch of the radial nerve. The aim of our study was to reveal the anatomical properties and especially morphometric measurements of the AF in cadavers. This study was performed on 55 cadaver upper extremities. The AF was classified macroscopically as either tendinous or membranous. The width, length and thickness of the AF were measured as the dimensions of the AF. The distance AF between the lateral epicondyle of the humerus and the AF was measured. The forearm length between the lateral epicondyle of the humerus and the styloid process of the radius was measured. The distance AF was divided by the forearm length to find the ratio AF. In 87% of the extremities the AF was tendinous, and in 13% it was membranous. The mean width, length and thickness of the AF were 10.13, 8.60 and 0.77 mm, respectively. The mean distance AF and forearm length were 46.23 and 233.17 mm, respectively. The mean ratio AF was 0.199 (approximately 1/5). These measurements of the dimensions of the AF may contribute to the anatomy of the AF. The surgeon may find the predicted distance AF of any upper extremity by dividing its forearm length by 5.     

The course and branching pattern of the deep branch of the radial nerve in relation to the supinator muscle in fetus elbow

We aimed to make first demonstration of the course and branching pattern of deep branch of the radial nerve (DBRN) in relation to the supinator muscle in the forearms of fetuses and make morphological measurements in both fetuses and adults. We carried out dissection on 80 radial nerves from 20 adult cadavers (16 males and 4 females), ranging from 30 to 56 years old and 20 formalin-fixed, spontaneously aborted fetuses (10 males and 10 females) without detectable malformations, ranging from 20 to 37 weeks of gestation. There were three different branching patterns of the DBRN in fetuses. It divided its terminal branches at entrance of the supinator in 2 (5%), after entry of the supinator in 4 (10%) and after the supinator in 34 (85%) forearms. The course was bilaterally same in fetuses. Dividing pattern at the entrance of the supinator was not seen in adults. Only 4 (10%) were seen at after entering to the supinator and 36 (90%) were seen at after the supinator. We saw in fetuses neither fibrous band deep from the extensor carpi radialis longus nor upper border of the supinator. We assume that these fibrous structures appear after birth, perhaps favored by physical exercise, such as repeated pronation–supination movements. We think that it is one of the reasons why DBRN compression has never been reported in children. This is the first fetal study about the course and branching pattern of the DBRN and there is a constant ratio (mean 4.3) between the measurements of the fetuses and adults.     

Redefining the proximal ulna anatomy

Purpose

Complex fractures of the olecranon have always been a difficult condition for treatment. Successful reconstruction depends on restoration of the anatomic contributors to stability. The purpose of this study was to define the proximal ulna anatomy in detail with respect to fracture fixation and arthroscopy.

Methods

In 50 normal adult ulnae (26 left, 24 right); posterior olecranon height (POH), olecranon width (OW), trochlear notch width (TW), the distances between the olecranon and the trochlear notch on radial and ulnar sides (RTH, UTH), and proximal ulnar angulations were measured with a ruler and a digital goniometer.

Results

The average POH was 24.6 mm, OW was 23.1 mm, TW was 22.3 mm, RTH was 16.2 mm, and UTH was 15.8 mm. The mean value for proximal ulna torsion angle (PUTA) was found 11.1°. The mean varus angulation was 9.3°. The average articular angle was 27.7° and proximal ulnar dorsal angulation (PUDA) was 8°.

Conclusions

The unique bony architecture of the proximal ulna presents particular difficulties for the implants used in fracture fixation and arthroplasty of the elbow. Knowing the detailed anatomy of the variations of proximal ulna will guide the surgeon to obtain a more reliable length of the olecranon and to offer a safe place for Kirschner wire replacement concerning humero-ulnar joint functionality. In this study, PUTA was also defined. The angle determines the rotation of the proximal ulna and it has a great importance for the movements of the joint. The measured angulations will help the surgeon to design the proper prosthesis for the maintenance of the functions of the elbow joint.     

An anatomic study of the dorsal forearm perforator flaps

Purpose

The posterior forearm is an excellent donor site for the vascular pedicled cutaneous flaps; yet, there is surprisingly little detailed anatomical information based on clinical decision making. This study was undertaken to evaluate the anatomical basis of the dorsal forearm perforator flaps and to provide anatomical landmarks to facilitate flap elevation.

Methods

Thirty cadavers were available to perform this anatomical study after arterial injection. Twenty fresh cadavers were injected with a modified lead oxide–gelatin mixture, selected for 3-dimensional reconstruction using special software (MIMICS) and the arterial territory measured with Scion Image. Other ten were injected with red latex preparation, and perforators were identified through dissection.

Results

(1) The average number of posterior interosseous artery cutaneous perforators in the dorsal forearm was 5 ± 2, the average diameter was (0.5 ± 0.1) mm, and the pedicle length was (2.5 ± 0.2) cm. The average cutaneous vascular territory was (22 ± 15) cm². Cutaneous perforators could be found along the line extending from the lateral epicondyle to the radial border of the head of ulna. (2) Dorsal branch of anterior interosseous artery supplied blood to distal third of dorsal forearm; its average diameter was 0.8 mm.

Conclusion

The free transplantation of the posterior interosseous perforator artery flaps or rotary flap pedicled by dorsal branch of anterior interosseous artery for defect reconstruction is feasible.     

Anatomical study of the medial patello-femoral ligament: landmarks for its surgical reconstruction

Purpose

The aim of this dissection study was to describe the anatomical insertions of the medial patello-femoral ligament (MPFL), and to assess its relationship with surrounding structures to improve its surgical reconstruction.

Methods

Twelve knees (7 cadavers) were included for the study. Measurements and general features of the MPFL were assessed: lengths, widths and insertions.

Results

The MPFL was found in all knees, presenting a triangular shape, and extending from the medial part of the patella to its femoral insertion (its length was of 59 ± 6.6 mm), distal to the adductor tubercle. The mean femoral insertion of the MPFL was 7.2 ± 2.7 mm proximal and 7.4 ± 4.0 mm posterior to the medial femoral epicondyle (MFE). It was also at a mean 11 ± 2.8 mm distal and 1.3 ± 2.1 mm posterior to the adductor tubercle, and 22 ± 6.4 mm anterior to the posterior condyle. We did not find any double-bundle organization on the patellar insertion. The width of the MPFL was 8.8 ± 2.9 mm at the femoral insertion, 27 ± 5.9 mm at the patellar insertion, and 12 ± 3.1 mm in the middle of the MPFL. The vastus medialis obliquus was found to be inserted on the superior part of the MPFL.

Conclusion

The adductor tubercle appeared to be a better landmark than the MFE for the femoral tunnel positioning during surgical reconstructions of the MPFL because it was easier to identify and its relationship with the femoral insertion of the MPFL was constant (10 mm below).     

Morphometric analysis of the proximal ulna using three-dimensional computed tomography and computer-aided design: varus,dorsal, and torsion angulation

Purpose

The proximal ulna, particularly the course of the posterior border, has a complex three-dimensional (3D) morphology which has been highlighted recently due to its clinical relevance in relation to surgical treatments. 3D computed tomography (CT) reconstruction and computer-aided design (CAD) based software can help to visualize the complex anatomy and thus aid the investigation of the more detailed morphology of the proximal ulna.

Methods

In our current study, 3D CT reconstruction images of 20 cadavers were imported into the 3D CAD program. Three morphologic angle parameters of the proximal ulna were measured including the dorsal, varus and torsion angulation. The torsion angulation was measured using the flat spot of olecranon dorsal aspect. We measured the total length of the ulna and the distance between the olecranon tip and the apex of dorsal and varus angulation. Furthermore, the thickness of olecranon was also measured for all the specimens.

Results

The results showed that the mean dorsal, varus, and torsion angulation was 4.3° (range 2.6°–5.9°), 12.1° (range 7.9°–17.6°), and 22.5° (range 16.6°–30.5°), respectively. The average length ratio of the dorsal and varus angulation apex to the total ulnar length was 26.4 % (range 19.8–30.7 %) and 32.7 % (range 27.5–37.5 %), respectively. The average of olecranon thickness at the proximal tip, mid-olecranon fossa, and at coronoid tip level was 17.8 mm (range 14.1–22.8 mm), 19.7 mm (range 15.8–23.1 mm), and 35.1 mm (range 27.9–41.8 mm), respectively.

Conclusion

In conclusion, variations in the proximal ulna have to be considered when anatomically contoured dorsal plates are applied. Knowledge of the 3D morphologic anatomy of the proximal ulna would provide important information on fracture reductions, and the design of a precontoured dorsal plate or a prosthetic ulnar stem.     

Variations of the radial recurrent artery of clinical interest

Purpose

The anatomy of the radial recurrent artery (RRA) is important for different clinical procedures: interventional cardiology and microsurgery of the forearm; however, few studies have analysed its morphology: number, course, relations and distribution.

Methods

The RRA was analysed in 332 upper limbs divided into two groups: (1) normal pattern of the arterial axis of the upper limb (266 cases), (2) associated with major arterial variations (66 cases).

Results

A second or accessory RRA existed in 31.2 % in group 1, and 30.3 % in group 2. In both groups, the second RRA originated from the brachial (100 %) and always (100 %) coursed behind the bicipital tendon. The accessory RRA supplied the brachioradialis, brachialis and biceps brachii muscles. The RRA in group 1, originated mostly from the radial artery (75 %), followed by radioulnar division and ulno-interosseous trunk. In group 2, the RRA arise from the brachioradial artery (65 %), or from the radial artery (in cases of ulnar or brachial artery variation). The course of the RRA behind the biceps brachii tendon was observed in 9.4 % of group 1 and in 6.1 % of group 2. The RRA supplied the brachioradialis, extensor carpi radialis longus and brevis, and supinator muscles. The RRA and accessory RRA anastomosed forming a ring around the biceps brachii tendon in 0.75 % in group 1 and in 13.6 % in group 2, the latter group having an important clinical interest.

Conclusions

The variability of the RRA may provide an advantage for microsurgical procedures of the elbow and disadvantage during transradial catheterism.     

The gluteal sling: an anatomical study

Introduction

Sciatic nerve palsy is a devastating complication which may be seen after acetabular exposure in total hip resurfacing via a posterior approach. An anatomical structure termed as the “gluteal sling” was suggested to play a role in sciatic nerve palsies during this operation. “Gluteal sling” is formed by the attachment of the deep fibers of the inferior part of the gluteus maximus on the gluteal tuberosity of the femur and the lateral intermuscular septum. It is suggested to be released to avoid such compressive injuries. The purpose of this study is to demonstrate how much of the gluteal sling should be released to decrease the tension on sciatic nerve during posterior hip arthroplasties. We also aimed to study the anatomical structures at risk during releasing procedure.

Materials and methods

The gluteal sling was examined in 17 sides of 9 adult cadavers. Its relation with the sciatic nerve, first perforating artery, the tip of greater trochanter and the ischial tuberosity were evaluated.

Results

The closest distance between the gluteal sling and the sciatic nerve was measured as 1.9 ± 0.6 cm. This point was corresponding to the distal 2/3 part of the gluteal sling. The distance of the proximal edge of the gluteal sling to the first perforating artery was 3.7 ± 0.9 cm, while its ascending branch was closer, being 1.8 ± 0.8 cm.

Conclusions

Theoretically, it is enough to release the proximal 2/3 of the gluteal sling to avoid its compression on the sciatic nerve. However, further clinical studies would need to be undertaken to properly determine the effects of this procedure.