Dual-portal endoscopic release of the transverse ligament in carpal tunnel syndrome: results of 411 procedures with special reference to technique, efficacy, and complications

OBJECTIVE

Endoscopic release of carpal tunnel syndrome is still under debate. The main advantages of the technique are considered to be minor postoperative pain and a more rapid postoperative recovery. Disadvantages are thought to be the impossibility of a direct median nerve neurolysis and a higher surgical complication rate, including injury to the median nerve.

METHODS

The results of 411 consecutive endoscopic carpal tunnel procedures performed between March 1995 and September 2004 are presented. All patients were prospectively followed.

RESULTS

In the present series, a success rate of 98.05% was observed. There was no permanent morbidity and, in particular, there was no injury of the median nerve. In four (0.97%) patients, the preoperative symptoms did not improve. In two (0.49%) of these patients, an incomplete release of the carpal ligament occurred. In another four patients (0.97%), a switch to open surgery was required.

CONCLUSION

The present data prove that the endoscopic technique is a safe and reliable technique for carpal tunnel surgery. The data do not support the current discussion of a higher risk of median nerve injury with endoscopic carpal tunnel surgery. Thus, for our group, the endoscopic technique represents the therapy of choice for the primary idiopathic carpal tunnel syndrome.

Defining worthwhile and desired responses to treatment of chronic low back pain

OBJECTIVE

To describe patients' perceptions of minimum worthwhile and desired reductions in pain and disability upon commencing treatment for chronic low back pain.

DESIGN AND SETTING

Descriptive study nested within a community-based randomized controlled trial on prolotherapy injections and exercises.

PATIENTS

A total of 110 participants with chronic low back pain. Interventions. Prior to treatment, participants were asked what minimum percentage reductions in pain and disability would make treatment worthwhile and what percentage reductions in pain and disability they desired with treatment.

OUTCOME MEASURES

Minimum worthwhile reductions and desired reductions in pain and disability.

RESULTS

Median (inter-quartile range) minimum worthwhile reductions were 25% (20%, 50%) for pain and 35% (20%, 50%) for disability. This compared with desired reductions of 80% (60%, 100%) for pain and 80% (50%, 100%) for disability. The internal consistency between pain and disability responses was high (Spearman's coefficient of association of 0.81 and 0.87, respectively). A significant association existed between minimum worthwhile reductions and desired reductions, but no association was found between these two factors and patient age, gender, pain severity or duration, disability, anxiety, depression, response to treatment, or treatment satisfaction.

CONCLUSIONS

Inquiring directly about patients' expectations of reductions in pain and in disability is important in establishing realistic treatment goals and setting benchmarks for success. There is a wide disparity between the reductions that they regard as minimum worthwhile and reductions that they hope to achieve. However, there is a high internal consistency between reductions in pain and disability that they expect.

Dental considerations for individuals with Down syndrome

Down syndrome is one of the most frequently encountered and easily recognizable of all developmental disabilities. Patients with Down syndrome exhibit mental retardation and often present with associated medical conditions, such as cardiac defects, immune deficiencies and musculoskeletal disorders. It is important for the dental practitioner to be familiar with the medical aspects of Down syndrome, as well as the potential behavioral issues. We present a brief review of Down syndrome for the dental provider and suggest that with a little knowledge and some patience, most private practitioners can easily accommodate these patients in their practice.

Head position and impact direction in whiplash injuries: associations with MRI-verified lesions of ligaments and membranes in the upper cervical spine

In the present study, we compared magnetic resonance imaging (MRI) findings of soft tissue structures in the upper cervical spine between whiplash-associated disorder (WAD) patients and population-based control persons, and examined whether MRI-verified abnormalities in WAD patients were related to accident-related factors hypothesized to be of importance for severity of injury. A total of 92 whiplash patients and 30 control persons, randomly drawn, were included. Information on the accident-related factors (i.e., head position and impact direction) was obtained by a questionnaire that was answered within 1 week after the accident. The MRI examination was performed 2-9 (mean 6) years after the accident. Focus was on MRI abnormalities of the alar and the transverse ligaments, and the tectorial and posterior atlanto-occipital membranes, graded 0-3. For all neck structures, the whiplash patients had more high-grade lesions (grade 2 or 3) than the control persons (Chi-square test, p < 0.055). An abnormal alar ligament was most common (66.3% graded 2 or 3). Whiplash patients who had been sitting with their head/neck turned to one side at the moment of collision more often had high-grade lesions of the alar and transverse ligaments (p < 0.001, p = 0.040, respectively). Severe injuries to the transverse ligament and the posterior atlanto-occipital membrane were more common in front than in rear end collisions (p < 0.001, p = 0.001, respectively). In conclusion, the difference in MRI-verified lesions between WAD patients and control persons, and in particular the association with head position and impact direction at time of accident, indicate that these lesions are caused by the whiplash trauma.

High-repetition cyclic loading is a risk factor for a lumbar disorder

Epidemiological data suggest that prolonged exposure to cyclic lumbar flexion elicits a chronic neuromuscular disorder and disability in workers. This study provides a physiological and biomechanical assessment of various repetitions of cyclic lumbar flexion sessions as a risk factor for development of an acute neuromuscular disorder. An in vivo feline model was subjected to 10 minutes of cyclic (0.25-HZ) loading, followed by a 10-minute rest period, repeated three times in one experimental group, six times in a second group, and nine times in the third group, followed by rest for 7 hours. Displacement of the lumbar viscoelastic tissue and reflex electromyographic (EMG) activity from the lumbar multifidus muscle were monitored. Creep developed and accumulated during each load/rest period and partially recovered during the subsequent rest. Loading periods were characterized by a decrease in reflex EMG activity with superimposed spasms. In the 7-hour recovery period, initial hyperexcitability was present in all groups, whereas only the six- and nine-repetition groups displayed significant delayed hyperexcitability, indicating the presence of acute inflammation. The mathematical model developed fit the data reasonably well, as the R2 values were generally near 0.90. It was concluded that the resulting delayed muscular hyperexcitability constitutes an acute neuromuscular disorder associated with exposure to many repetitions of cyclic lumbar flexion. The acute disorder can become chronic if not allowed sufficient rest to resolve itself. Workers engaged in cyclic lumbar flexion (e.g., loading/unloading, assembly workers) should avoid long-term exposure in order to prevent the development of a chronic neuromuscular condition known as cumulative trauma disorder.

The effect of interspinous ligament integrity on adjacent segment instability after lumbar instrumentation and laminectomy--an experimental study in porcine model

Eight fresh porcine lumbar spines received a posterior instrumentation at L4-L5 using pedicle screw-rod system. Each specimen was tested utilizing laminectomies of varying extent. Group A (Integrity) preserved the spinous process and interspinous ligament; Group B (Partial laminectomy) removed the inferior portion of L4 spinous process and preserved the interspinous ligament of L3-L4; Group C (Complete laminectomy) removed the entire L4 spinous process. Hydraulic testing machine was used to generate an increasing moment up to 8400 N mm in flexion and extension. The intervertebral displacement on the superior adjacent disc between L3-L4 was measured using an extensometer. Under extension, no significant difference in the intervertebral displacement was observed among three different models of laminectomy. However, under flexion, the intervertebral displacement on adjacent disc with complete laminectomy was statistically larger than those of integrity and partial laminectomies (P=0.000976 and P=0.0363, respectively). No difference was found between integrity and partial laminectomy groups (P>0.05). This study implies that an instrumented spine with integrity of posterior complex is less likely to develop adjacent instability than a spine with destruction of the anchoring point for supraspinous ligament.

Minicore myopathy with ophthalmoplegia caused by mutations in the ryanodine receptor type 1 gene

BACKGROUND

Minicore myopathy (multi-minicore disease [MmD]) is a congenital myopathy characterized by multifocal areas with loss of oxidative activity on muscle biopsy. MmD is clinically heterogeneous and distinct phenotypes have been associated with recessive mutations in either the selenoprotein N (SEPN1) or the skeletal muscle ryanodine receptor (RYR1) gene, also implicated in central core disease and malignant hyperthermia. External ophthalmoplegia is an additional finding in a subset of patients with MmD.

OBJECTIVE

To clinically and genetically examine families with MmD and external ophthalmoplegia.

METHODS

The authors investigated 11 affected individuals from 5 unrelated families. Clinical, histopathologic, and imaging studies were performed and RYR1 haplotyping and mutational analysis were carried out.

RESULTS

All patients had multiple cores involving the entire fiber diameter on longitudinal sections. Weakness and wasting in the shoulder girdle, scoliosis, moderate respiratory impairment, and feeding difficulties were prominent. In contrast to SEPN1-related myopathies, soleus was more severely affected than gastrocnemius on muscle MRI. Haplotyping suggested linkage to the RYR1 locus in informative families and mutational screening revealed four novel RYR1 mutations in three unrelated families; in addition, functional haploinsufficiency was found in one allele of two recessive cases.

CONCLUSION

These findings expand the phenotypic spectrum associated with mutations in the skeletal muscle ryanodine receptor (RYR1) gene. Recessive mutations of domains commonly affected in malignant hyperthermia appear to be particularly prevalent in multi-minicore disease with external ophthalmoplegia and might suggest a different pathomechanism from that involved in central core disease.

[Research advance of ligament injury and ligament healing]

OBJECTIVE

To introduce the research advance of the ligament injury and ligament healing.

METHODS

Recent original articles related to such aspects of ligament were reviewed extensively.

RESULTS

The ligament properties would be influenced when the situations of the biochemistry and biomechanics had changed. Injuries to ligaments induce a healing response that is characterized by scar formation. Graft could not recovery the ultrastructure, anatomy and biomechanics of the normal ligament.

CONCLUSION

The healing ligament is weaker than normal one, and the graft could not reconstruct normal ligament at present.

Development of a Force Amplitude- and Location-Sensing Device Designed to Improve the Ligament Balancing Procedure in TKA

To improve the ligament balancing procedure during total knee arthroplasty a force-sensing device to intraoperatively measure knee joint forces and moments has been developed. It consists of two sensitive plates, one for each condyle, a tibial base plate and a set of spaces to adapt the device thickness to the patient-specific tibiofemoral gap. Each sensitive plate is equipped with three deformable bridges instrumented with thick-film piezoresistive sensors, which allow accurate measurements of the amplitude and location of the tibiofemoral contact forces. The net varus-valgus moment is then computed to characterize the ligamentous imbalance. The developed device has a measurement range of 0-500 N and an intrinsic accuracy of 0.5% full scale. Experimental trials on a plastic knee joint model and on a cadaver specimen demonstrated the proper function of the device in situ. The results obtained indicated that the novel force-sensing device has an appropriate range of measurement and a strong potential to offer useful quantitative information and effective assistance during the ligament balancing procedure in total knee arthroplasty.

Whiplash-associated disorders impairment rating: neck disability index score according to severity of MRI findings of ligaments and membranes in the upper cervical spine

The aim of this study was to explore whether reported pain and functional disability in whiplash-associated disorders (WAD) patients is associated with lesions to specific soft tissue structures in the upper cervical spine, as assessed by MRI. Pre-selected structures for MRI assessment included the alar ligaments, the transverse ligament, the tectorial and the posterior atlanto-occipital membranes. The questionnaire employed was a modification of the Oswestry Low Back Pain Index. It was comprised of ten single items related to pain and activity of daily living. Ninety-two whiplash patients and 30 control persons, randomly drawn, were included. WAD patients reported significantly more pain and functional disability than the controls, both for total score and each of the ten single items. In the WAD patients, MRI lesions to the alar ligaments showed the most consistent association to the reported pain and disability. Lesions to other structures often occurred in combination with lesions to the alar ligaments. Lesions to the transverse ligament and to the posterior atlanto-occipital membrane also appeared to be related to the NDI score, although the association was weaker than for the alar ligament. The disability score increased with increasing number of abnormal (grade 2-3) structures. These results indicate that symptoms and complaints among WAD patients can be linked with structural abnormalities in ligaments and membranes in the upper cervical spine, in particular the alar ligaments.

A hypothesis of chronic back pain: ligament subfailure injuries lead to muscle control dysfunction

Clinical reports and research studies have documented the behavior of chronic low back and neck pain patients. A few hypotheses have attempted to explain these varied clinical and research findings. A new hypothesis, based upon the concept that subfailure injuries of ligaments (spinal ligaments, disc annulus and facet capsules) may cause chronic back pain due to muscle control dysfunction, is presented. The hypothesis has the following sequential steps. Single trauma or cumulative microtrauma causes subfailure injuries of the ligaments and embedded mechanoreceptors. The injured mechanoreceptors generate corrupted transducer signals, which lead to corrupted muscle response pattern produced by the neuromuscular control unit. Muscle coordination and individual muscle force characteristics, i.e. onset, magnitude, and shut-off, are disrupted. This results in abnormal stresses and strains in the ligaments, mechanoreceptors and muscles, and excessive loading of the facet joints. Due to inherently poor healing of spinal ligaments, accelerated degeneration of disc and facet joints may occur. The abnormal conditions may persist, and, over time, may lead to chronic back pain via inflammation of neural tissues. The hypothesis explains many of the clinical observations and research findings about the back pain patients. The hypothesis may help in a better understanding of chronic low back and neck pain patients, and in improved clinical management.

A randomized controlled trial of surgery vs steroid injection for carpal tunnel syndrome

BACKGROUND

Decompressive surgery and steroid injection are widely used forms of treatment for carpal tunnel syndrome (CTS) but there is no consensus on their effectiveness in comparison to each other. The authors evaluated the efficacy of surgery vs steroid injection in relieving symptoms in patients with CTS.

METHODS

The authors conducted a randomized, single blind, controlled trial. Fifty patients with electrophysiologically confirmed idiopathic CTS were randomized and assigned to open carpal tunnel release (25 patients) or to a single injection of steroid (25 patients). Patients were followed up at 6 and 20 weeks. The primary outcome was symptom relief in terms of the Global Symptom Score (GSS), which rates symptoms on a scale of 0 (no symptoms) to 50 (most severe). Nerve conduction studies and grip strength measurements were used as secondary outcome assessments.

RESULTS

At 20 weeks after randomization, patients who underwent surgery had greater symptomatic improvement than those who were injected. The mean improvement in GSS after 20 weeks was 24.2 (SD 11.0) in the surgery group vs 8.7 (SD 13.0) in the injection group (p < 0.001); surgical decompression also resulted in greater improvement in median nerve distal motor latencies and sensory nerve conduction velocity. Mean grip strength in the surgical group was reduced by 1.7 kg (SD 5.1) compared with a gain of 2.4 kg (SD 5.5) in the injection group.

CONCLUSION

Compared with steroid injection, open carpal tunnel release resulted in better symptomatic and neurophysiologic outcome but not grip strength in patients with idiopathic carpal tunnel syndrome over a 20-week period.

[The enthesis. Physiological morphology, molecular composition and pathoanatomical alterations]

The composition of the extracellular matrix in tendons and ligaments is directly related to the mechanical environment. Local compression triggers functional adaptation that leads to cartilage-specific transformation of the tissue. The molecular composition of the extracellular matrix at the enthesis is related to the amount of stress and to the geometry of the insertion. Comparison of physiologically and non-physiologically loaded entheses shows that only certain molecules occur under relatively high amounts of local compressive stress. The occurrence of certain cartilage specific molecules is clinically relevant, because some of these molecules have been identified as autoantigens during the autoimmune response in patients with rheumatoid arthritis. These molecules constitute potential targets for the manifestation of rheumatoid arthritis at fibrocartilaginous entheses.

Quality of sex life in women with endometriosis and deep dyspareunia

OBJECTIVE

To characterize sexual function among women with endometriosis and deep dyspareunia (DD).

DESIGN

Cross-sectional survey.

SETTING

University teaching hospital.

PATIENT(S)

Three-hundred nine women undergoing surgery because of infertility, pelvic pain, or adnexal masses. Three groups of patients with DD were created: women with deep infiltrating endometriosis of the uterosacral ligament (group U), women with endometriosis without uterosacral ligament lesions (group E), and controls (group C).

INTERVENTION(S)

Laparoscopy.

MAIN OUTCOME MEASURE(S)

Sexual function questionnaire.

RESULT(S)

The prevalence of DD since the first intercourse was significantly higher among women with endometriosis than in controls (P=.029). When group U was compared with group E and C, the pain score was higher, the number of intercourses per week was reduced, the orgasm was less satisfying, and the patients felt less relaxed and fulfilled after sex. No significant difference was observed in pain score and coital frequency between subjects with monolateral and bilateral lesions of the uterosacral ligament.

CONCLUSION(S)

Among subjects with DD, those with deep infiltrating endometriosis of the uterosacral ligament have the most severe impairment of sexual function; the presence of bilateral lesions does not influence the severity of the symptoms. Women with endometriosis have frequently suffered DD during their entire sex lives.

Structural properties of reconstruction constructs for the interosseous ligament of the forearm

PURPOSE

The Essex-Lopresti fracture-dislocation, also termed longitudinal radioulnar dissociation (LRUD), results in major functional impairment from pain and limitation of motion at the wrist and elbow. Interosseous ligament (IOL) reconstruction has been proposed to help treat LRUD and restore forearm stability. The objective of this study was to evaluate the biomechanical structural properties of 3 different IOL reconstruction constructs and of the intact IOL for comparison.

METHODS

Structural tensile testing was performed on 24 fresh-frozen cadaveric forearms with 4 different forearm conditions: IOL intact and IOL reconstructed with Achilles tendon, flexor carpi radialis (FCR) tendon, and bone-patellar tendon-bone. Isolated radius-IOL-ulna constructs were loaded to failure in a materials testing machine with force applied along the local fiber direction.

RESULTS

Stiffness in the intact IOL was 129 +/- 31 N/mm, which was significantly stiffer than any of the constructs tested. The intact IOL was 8 times stiffer than the Achilles tendon construct, 7 times stiffer than the FCR construct, and 3 times stiffer than the bone-patellar tendon-bone construct. The Achilles tendon and FCR constructs were similar to each other biomechanically but the bone-patellar tendon-bone construct was slightly stiffer than the Achilles tendon and FCR constructs.

CONCLUSIONS

All graft constructs tested were inferior structurally to the intact IOL. The results of this study provide a biomechanical basis for graft selection for reconstruction of the IOL.

Reconstruction of the interosseous ligament restores normal forearm compressive load transfer in cadavers

PURPOSE

Longitudinal radioulnar dissociation may result when compressive load to the hand causes excessive proximal migration of the radius with interosseous ligament (IOL) disruption and radial head fracture. Although radial head salvage or arthroplasty and temporary distal radioulnar joint pinning constitute the current treatment for this injury IOL reconstruction has been proposed to restore normal forearm mechanics. To help provide a biomechanical basis for IOL reconstruction we measured load transfer and proximal migration of the radius with the IOL intact, cut, and reconstructed while leaving the radial head intact.

METHODS

We dissected the central third of 12 normal cadaveric forearms to bone-IOL-bone. We applied 136 N of compressive load to the hand and measured proximal radial migration and 3-dimensional force vectors acting in the distal radius, distal ulna, IOL, proximal radius, and proximal ulna. Experiments were performed in neutral forearm rotation and neutral elbow varus-valgus. The protocol was repeated with the IOL intact, cut, and reconstructed with single and double flexor carpi radialis allografts.

RESULTS

With the IOL intact 94% +/- 3 % of hand load was in the distal radius with 75% +/- 2% was transmitted to the proximal radius. With the IOL cut 92% +/- 2% of hand load was in the distal radius and this was unchanged at the proximal radius. With single flexor carpi radialis reconstruction 94% +/- 3% of hand load was in the distal radius and 80% +/- 2% was in the proximal radius; with double flexor carpi radialis reconstruction these numbers changed to 95% +/- 3% and 74% +/- 2%, respectively. Forces in the forearm were mainly in the longitudinal and transverse directions with negligible components in the dorsal-volar direction. Transverse force in the IOL was about half that of the longitudinal force in the intact and reconstructed states.

CONCLUSIONS

When the IOL is cut and load is applied to the hand the unloading of the proximal radius and the transversely directed force that compresses normally across the proximal and distalradioulnar joints is lost. Reconstruction of the IOL can restore the normal load transfer characteristics. These data help provide a biomechanical basis for IOL reconstruction. Further research on the biomechanics of IOL reconstruction in the setting of radial head replacement along with clinical evaluation is needed.

Ligamentous versus physeal failure in murine medial collateral ligament biomechanical testing

This study examines the age at which a femoral physeal failure ceased to occur in a mouse model of medial collateral ligament (MCL) testing. Biomechanical testing of the MCL with load to failure can result in physeal failure rather than MCL failure in skeletally immature animals. Failure mode depended significantly on age (p<0.05). Sixty percent of the knees tested at 4 months failed at the physis rather than at the ligament, whereas, only ten percent of the knees tested at 5 and 6 months failed at the physis. The mean ultimate force to failure for the specimens in which the failure occurred at the ligament was 8.1 N with a higher values for the right side versus the left (p<0.05). For the specimens in which the failure occurred at the physis, the mean ultimate force to failure was 11.2 N. We now consider that 5 month old mice are functionally skeletally mature and old enough to be tested biomechanically with few failures at the physis.

Sinus tarsi syndrome and subtalar joint instability

Sinus tarsi syndrome is a poorly understood term in the orthopedic world. It is thought of as a painful condition of the sinus tarsi that often responds to corticosteroid injection and is associated with a feeling of instability in the hindfoot. Despite references in the literature, there is no agreement on pathognomonic history, clinical tests, or imaging studies that could help in confirming the diagnosis or establishing the etiology. Some authors relate the clinical condition of sinus tarsi syndrome with instability of the subtalar joint.

Ligament Strains Predict Knee Motion After Total Joint Replacement

A passive forward kinematics knee model was used to predict knee motion of a total joint replacement. Given ajoint angle, maps of articular surfaces, and patient-specific ligament properties, this model predicted femorotibial contact locations based on the principle of ligament-strain minimization. The model was validated by physical experiments on a commonly implanted knee prosthesis, showing excellent correspondence between the model and actual physical motion. Results suggest that the knee prosthesis studied required an intact posterior cruciate ligament to induce the desirable roll-back motion, and that a single-bundle model of major knee ligaments generated kinematics similar to that of a multibundle ligament model. Implications are that a passive model may predict knee kinematics of a given patient, so it may be possible to optimize the implantation of a prosthesis intraoperatively.

Novel treatment of basilar invagination resulting from an untreated C-1 fracture associated with transverse ligament avulsion

✓ The authors describe the case of a traumatic C-1 ring fracture and transverse ligament injury in an otherwise healthy adult woman; the lesion was essentially untreated for 3 months and resulted in basilar invagination. On presentation 3 months postinjury, the patient complained of severe increasing suboccipital pain and a grinding sensation in her upper neck. Axial computerized tomography (CT) scans revealed a C-1 ring fracture, basilar invagination with the dens abutting the clivus, and significant lateral splaying of the C-1 lateral masses. Flexion—extension radiography demonstrated abnormal motion at the atlantoaxial junction. A unique surgical technique was used to address simultaneously the C1–2 instability, the displaced C-1 fracture, and basilar invagination without having to perform occipital fixation. The authors believe that an understanding of the mechanism of the cranial settling in this case (further splaying of the C-1 lateral masses and downward migration of the occipital condyles) permitted full reduction of the deformity; this was accomplished by performing a horizontal reduction of the C-1 lateral masses, using direct C-1 lateral mass screws, a rod compressor, and a cross-link. Postoperative CT scanning confirmed the success of reduction. The results in this report highlight a rare but important complication of untreated C-1 fracture and ligament disruption, and the authors describe a novel treatment technique with which to restore vertical alignment and preserve occipital C-1 motion. A variation of this technique may also be used to treat Type II transverse ligament injuries associated with C-1 ring fractures as an alternative to halo immobilization.

The entheses: histology, pathology, and pathophysiology

The entheses are the sites of attachment of ligaments, tendons, and joint capsules to bone. Their ubiquitous distribution throughout the body explains the considerable clinical and radiological polymorphism of entheseal diseases. In addition to aging and mechanical factors, many disorders related to a vast array of pathophysiological mechanisms can produce entheseal disease. The spondyloarthropathies provide the most striking examples of entheseal involvement in inflammatory joint disease. Over the last few decades, major advances have shed light on the biochemical composition of the entheses, their histological features, their mechanical role, and their evaluation by ultrasonography and magnetic resonance imaging. These new insights have generated valuable hypotheses about the pathogenesis of spondyloarthropathies.

Neurolysis for meralgia paresthetica: an operative series of 45 cases

BACKGROUND

Failure of symptom relief after neurolysis for meralgia paresthetica (MP) is reported frequently, yet systematic outcome analysis is limited in the modern literature. The present operative series of 45 cases aims to address this issue.

METHODS

From 1996 to 2000, all patients who had neurolysis for MP by our senior author were enrolled in the study. Nerve entrapment was confirmed preoperatively by electrophysiological studies or a positive response to local anesthetic and steroid injection. Attention to the anatomical variability of the lateral femoral cutaneous nerve was made during nerve exploration. Decompression of the nerve was performed at the level of the iliac fascia, the inguinal ligament, and the fascia of the thigh distally. The outcome of surgery was assessed 6 weeks after the procedure followed by 3 monthly intervals if symptoms persisted. Telephone interviews were conducted to assess long-term results.

RESULTS

Forty-five decompressive procedures were performed in 42 patients over the 5-year period. The average duration of symptoms was 31 (2.5-180) months. All patients were followed for an average of 4.1 years. Complete and partial symptom improvements were noted in 33 (73%) and 9 (20%) cases, respectively. No recurrence was reported. Analysis of clinical variables demonstrated that the duration of symptoms preoperatively did not affect the rate of complete symptom relief, but obese patients (body mass index > 30) was 6 times more likely to have (odds ratio 6.16, P = 0.04) incomplete relief after surgery at long-term follow-up.

CONCLUSION

High success rate was recorded in our series of 45 cases. Prolonged duration of symptoms did not preclude favorable outcome but obesity had a negative association with good outcome.

The tensile strength of Cooper's ligament suturing: comparison of abdominal and transvaginal techniques

This study was designed to compare the strength and position of sutures anchored into Cooper's ligament utilizing a minimally invasive transvaginal suturing technique, versus the 'open' abdominal approach. In 12 fresh cadavers, Cooper's ligament was accessed via abdominal and vaginal incisions. After randomization, polytetrafluoroethylene (00) sutures were spaced along one ligament with the transvaginal device (n=36). Contralaterally, sutures were placed abdominally (n=36). Progressive load was applied until suture breakage or dislodgement, and tensile strength was measured using a digital tensiometer. Peak tension averaged 14.5 psi for abdominal and 12.96 psi for vaginal (p=0.28). Suture breakage rather than ligament 'pullout' was more likely for abdominal (95 vs. 56%, p=0.0001). Vaginal and abdominal sutures demonstrated nearly identical mean distances from mid-symphysis (4.62 vs. 4.24 cm, p=0.56). Peak tension was not correlated with suture location (r2=0.17, p=0.28). We conclude that transvaginal suturing, using the minimally invasive device, achieved similar tensile strength and position to the open technique. Transvaginal sutures were associated with greater likelihood of ligament 'pullout' before suture breakage under maximal load; however, the clinical implications of this finding are uncertain.

Étude objective de résistance des ligaments pelviens utilisés dans les cures de prolapsus et d'incontinence urinaire d'effort

OBJECTIVE

Underline the objective strength of the pelvic ligaments.

PATIENTS AND METHODS

Twenty nine human female pelvis cadavers, whose storage conditions differed, were used in our study. In each cadaver we dissected all the ligaments used in pelvic surgery. A subjective clinical evaluation of the ligament properties was performed by visual observation as well as by finger palpation. Ligaments were classified into three groups in terms of thickness and apparent strength following finger palpation, high, doubtful and low apparent quality ligaments. Then a suture taking the entire ligament switched the ligaments and a force was applied on the vagina axis until tearing. The device used for strength measurement during traction was a Samson type force gauge, which was developed for the purpose of our study. Results were given in Newtons.

RESULTS

We found a great variability in the values obtained at tearing with maximal values at 200 newtons and minimal at 22. Individually measured, ligament strength varied between individuals, and for a same patient between the type of ligaments and the side. The pre-vertebral ligament was on average the strongest. For bilateral ligaments, there was no difference between the left and right side. The iliopectineal ligament was statistically significantly stronger than sacrospinous and arcus tendineus of pelvic fascia. There was a correlation between subjective evaluation and objective strength measurements.

DISCUSSION AND CONCLUSION

We performed the only study of the strength of pelvic ligaments at tearing. These are, however, routinely used in the cure of prolapse and urinary incontinence. Our results show that there is a great variability in strength between individuals, and for a same patient between the types of ligaments and side. These observations could explain some of the surgical intervention failures and demonstrate the importance of per-operative strength evaluation. Per-operative subjective evaluation on strength is related to objective measurements and could be used to determine the type of ligaments to be used for surgical assembly suspension.

Influence of ligament stiffness on the mechanical behavior of a functional spinal unit

Data on the stiffnesses of spinal ligaments are required for analytical studies on the mechanical behavior of spinal segments. Values obtained experimentally vary widely in the literature. A finite element model of an L3/L4 functional spinal unit was used to determine the influence of ligament stiffness on intersegmental rotation and forces in the ligaments. The lowest values for ligament stiffness selected from the literature were used in one set of calculations, and the highest values were simulated in a second set. The nonlinear model was loaded with pure moments of 7.5 and 15 Nm in the three main anatomical planes. The mechanical behavior of the functional spinal unit was strongly influenced by ligament stiffness. In some cases, a ligament with low stiffness does not carry any load, while the same ligament with high stiffness has to carry a high load. This indicates that finite element models of spinal segments have to be validated and that a realistic quantitative prediction of ligament forces is extremely difficult.