The internervous safe zone for incision of the capsule of the hip. A cadaver study

Regional Anesthesia for Hip Arthroscopy

Pain after hip arthroscopy can be severe, yet we lack a consensus method for non-narcotic analgesia. Here we describe anatomic elements of hip arthroscopy and our current understanding of the relevant sensory innervation as a prelude to the evaluation of locoregional analgesic techniques. Many regional nerve blocks and local anesthetic infiltration techniques are reviewed, including 2 newer ultrasound fascial plane blocks. Further study of targeted, motor-sparing approaches, either ultrasound-guided or under direct surgical visualization is needed.

Comparison of the Analgesic Effect of Pericapsular Nerve Group Block and Lumbar Erector Spinae Plane Block in Elective Hip Surgery

Background and Objectives: The aim of this study was to compare the effectiveness of pericapsular nerve group (PENG) and lumbar erector spinae plane (L-ESP) blocks, both administered with a high volume (40 mL) of local anesthetic (LA), for multimodal postoperative analgesia in patients undergoing hip surgery. Materials and Methods: This was a prospective, double-blind, randomized study that included 75 adult patients who were divided into three equal groups: control, PENG, and L-ESP. The study compared pain intensity, morphine consumption, time to first morphine request, and postoperative satisfaction between the control group, which received standard multimodal analgesia, and the block groups, which received PENG or L-ESP block in addition to multimodal analgesia. The numerical rating scale (NRS) was used to measure pain intensity. Results: The results showed that the block groups had lower pain intensity scores and morphine consumption, a longer time to the first morphine request, and higher postoperative satisfaction compared to the control group. The median maximum NRS score during the first 12 h was four in the control group, two in the PENG group, and three in the L-ESP group. The control group (21.52 ± 9.63 mg) consumed more morphine than the two block groups (PENG, 11.20 ± 7.55 mg; L-ESP, 12.88 ± 8.87 mg) and requested morphine 6.8 h earlier and 5 h earlier than the PENG and L-ESP groups, respectively. The control group (median 3) had the lowest Likert satisfaction scores, while the PENG group (median 4) had the lowest NRS scores (L-ESP, median 4). Conclusions: The application of PENG or L-ESP blocks with high-volume LA in patients undergoing hip surgery reduces the need for postoperative analgesia and improves the quality of multimodal analgesia.

Effectiveness of a PENG catheter and the implications and a complication of tunnelling

Pericapsular nerve group (PENG) block is a recently developed technique for analgesia for hip surgeries. We chose to use a PENG catheter for effective analgesia perioperatively. In this case report, we performed PENG catheter for a patient posted for hip hemiarthroplasty. During the process of tunnelling after securing the catheter, we accidentally sheared the catheter and had to redo the procedure. The patient was comfortable during their stay with minimal pain. This case report emphasises the importance of securing a catheter in providing prolonged analgesia and also the importance of dealing with complications due to the procedure itself.

Juxtaneural ganglia arising from the hip joint: focus on magnetic resonance imaging findings and clinical manifestations

OBJECTIVE

To present cases of juxtaneural ganglia arising from the hip with a discussion of the magnetic resonance imaging (MRI) findings, presenting symptoms, and possible treatment option.

MATERIALS AND METHODS

Two radiologists performed a consensus review of MRI scans obtained between January 2013 and March 2021 to identify patients with juxtaneural ganglia around the hip. A total of 11 patients with 11 juxtaneural ganglia were identified. Medical records and MRI findings were retrospectively reviewed.

RESULTS

Eight patients had lesions involving the sciatic nerve, and three patients had lesions involving the obturator nerve. Sciatic ganglia arose from a paralabral cyst in the posteroinferior quadrant and continued through a narrow channel running along the posterior acetabulum, showing increased diameter in the sciatic foramen and intrapelvic portion. Obturator ganglia showed a J- or reverse J-shape on the coronal imaging plane and extended from a paralabral cyst in the anteroinferior quadrant via the obturator canal. Nine patients (9/11, 81.8%) had symptoms resembling those of lumbosacral radiculopathy. Four patients underwent arthroscopic surgery, and one patient underwent ultrasound-guided aspiration, all of whom showed partial improvement. Spontaneous decrease in the extent of the ganglion was observed in three patients (3/11, 27.3%).

CONCLUSION

This article describes rare cases of juxtaneural ganglia arising from the hip joint and involving the sciatic and obturator nerves. The lesions share similar MRI findings, and each type of cyst (sciatic or obturator ganglia) involves a specific labral quadrant.

Intraneural ganglion cysts originating from the hip joint: A single-center experience

INTRODUCTION/AIMS

Intraneural ganglion cysts (INGCs) are non-neoplastic mucinous cysts within the epineurium of peripheral nerves. Characteristics of INGCs around the hip joint have not been adequately described. We aimed to describe clinical features, imaging findings, and treatment outcomes in patients with INGCs originating from the hip joint.

METHODS

We retrospectively included cystic lesions around the hip joint satisfying the following inclusion criteria over 6 years: (1) multilocular elongated hyperintense cystic mass on T2-weighted imaging; and (2) distribution along the course of the peripheral nerve and its branches on magnetic resonance imaging (MRI).

RESULTS

Six patients with an INGC around the hip joint were identified. Parent peripheral nerves were the sciatic nerve (four patients), the superior gluteal nerve (one patient), and the nerve to quadratus femoris (one patient). Buttock, groin, or lower extremity pain/paresthesias were the initial symptoms in all patients. INGCs within the articular branches of the hip joint were identified on MRI. Four patients underwent arthroscopic debridement and capsulotomy. All patients showed generally favorable outcome regardless of treatment.

DISCUSSION

Physicians should consider the possibility of INGCs originating from the hip joint as a cause of nontraumatic hip, buttock, or lower extremity pain. This can occur in any nerve innervating the hip joint, and usually it originates in the posterior capsule of the hip joint. Arthroscopic surgery shows promising results; however, more information about the surgical technique and long-term follow-up results are needed.

Regional Anesthesia for Hip Arthroscopy

Pain after hip arthroscopy can be severe, yet we lack a consensus method for non-narcotic analgesia. Here we describe anatomic elements of hip arthroscopy and our current understanding of the relevant sensory innervation as a prelude to the evaluation of locoregional analgesic techniques. Many regional nerve blocks and local anesthetic infiltration techniques are reviewed, including 2 newer ultrasound fascial plane blocks. Further study of targeted, motor-sparing approaches, either ultrasound-guided or under direct surgical visualization is needed.

Do serum markers correlate with invasiveness of the procedure in THA? A prospective randomized study comparing direct anterior and lateral approaches

BACKGROUND

Advantages of minimally invasive approaches for total hip arthroplasty are still matter of debate. Serum markers have been assessed as objective method to quantify muscle damage after surgery but in literature ambiguous results have been reported. The aim of this prospective randomized study was to: 1) compare serum markers elevation between a minimally invasive direct anterior approach (DAA) and a direct lateral approach (DLA); 2) to establish a correlation between serum markers increase and other perioperative variables.

HYPOTHESIS

A lesser elevation of markers could be found in patients who underwent a minimally invasive DAA.

PATIENTS AND METHODS

Seventy patients were enrolled and randomly divided in two groups according to the type of the approach. All patients were treated with the same implant by the same surgeon and received the same rehabilitation protocol. Demographic data, preoperative Harris Hip Score (HHS) and operative time were recorded. Myoglobin, creatine kinase MB (CK-MB), troponin I, C-reactive protein (CRP), haemoglobin (HB) and pain levels were measured pre- and postoperatively.

RESULTS

Mean postoperative rise were 524.9±134.6 and 667.8±409.5 for myoglobin, 4.8±2.5 and 6.6±3.7 for CK-MB, and 16.9±5.3 and 15.4±6.4 for PCR, in DAA and DLA groups, respectively. In both groups, postoperatively values were significantly higher than preoperatively (p<0.05). Comparing the two groups, no significant differences in serum markers elevations were found. A significantly lower postoperative pain was found in DAA group than in DLA group (2.9 vs. 4.2 and 2.7 vs. 3.6 in second and third day, respectively (p<0.05)). No significant correlation was present between the serum marker elevations and age, BMI, HHS, operative time, HB or pain levels (p>0.05).

CONCLUSION

Serum markers of muscle damage and inflammation increased in the postoperative period without significant differences between DAA and DLA, even though overall trend was higher in DLA group. The DAA group had significantly lower levels of postoperative pain. No significant correlation between pain and serum markers levels was found.

LEVEL OF EVIDENCE

I; randomized study.

Overview of the Innervation of the Hip Joint

The innervation of the hip joint has been investigated for over 200 years by anatomists and clinicians. Knowledge of the distribution and location of these nerves relative to anatomic landmarks visible with image guidance is important for optimizing nerve blocks and radiofrequency ablation procedures. In this article, the innervation of the anterior and posterior hip joint is reviewed, focusing on the source of articular branches, their course, termination, and relationship to anatomic landmarks. The innervation of the hip joint is multifaceted, with articular nerves originating from many sources in close proximity to and distant from the hip joint.

From emergency department to operating room: interventional analgesia techniques for hip fractures

PURPOSE OF REVIEW

To provide an update on pain management options with regional anesthesia for patients with hip fractures at the emergency department (ED).

RECENT FINDINGS

Patients who sustain a hip fracture are typically admitted and diagnosed in the ED before being transferred to the operating room for surgery. Studies have clearly demonstrated the ability of the fascia iliaca compartment blocks (FICBs) and femoral nerve blocks (FNBs) to reduce pain and the risk of an acute confusional state. Their administration at an early stage of the patient's trajectory in the ED is beneficial. Recent anatomical studies contributed new knowledge of nociception in the hip joint, which allowed the development of more specific infiltration analgesia techniques without muscle weakness (e.g., pericapsular hip blocks). Further research on the timing of nerve blocks and an evaluation of new motor sparing techniques is indicated.

SUMMARY

FICB and FNB are established and recommended techniques in pain management for hip fracture patients. Their use early on in the ED may improve patient comfort and outcome. Pericapsular nerve hip blocks could provide a relevant alternative in future pain management in this group of patients.

Capsular Healing in Interportal and Periportal Capsulotomy Methods of Hip Arthroscopy

Objective

To evaluate the midterm outcomes and the capsular healing in patients who had interportal capsulotomy versus periportal capsulotomy of hip arthroscopy.

Methods

Retrospectively reviewed 33 patients with labral tear received hip arthroscopy, with an average age of 41 (27‐67) years, including 13 cases of Cam deformity and three cases of Pincer deformity. All patients had positive sign of flexion adduction internal rotation or flexion abduction external rotation. With MRI and radiographic (CT, X plain) imageological examination. MRI showed that all patients had labral tear. Radiographic finding (CT, X plain) showed the pathological changes of acetabular and femoral neck osteophyte. One group with 23 patients were treated with periportal capsulotomy. Another group with 10 patients were treated with interportal capsulotomy. All patients did not close the capsule. Clinical outcomes were measured with the Hip Outcome Score Activities of Daily Living (HOS‐ADL) and the modified Harris Hip Score (mHHS), patient satisfaction measured with visual analogue scale (VAS). The healing of the capsule was evaluated by MRI. MRI showed continuous capsular indicated healing, discontinuous capsular indicated unhealing. Postoperatively 6 months, mHHS and HOS‐ADL were obtained. Randomized controlled trials were used in this study for analysis.

Results

All patients were followed up with average time of 9.3 months(3‐29 months). The postoperative symptoms were obviously relieved, the VAS decreased from (4.9 ± 0.6) to (1.2 ± 0.2) after 3 months postoperative. Follow up 6 months post‐operation, patients in the interportal group, the mHHS and HOS‐ADL scores improvement were respectively 69.4 ± 9.3 & 70 ± 8.8 pre‐operation, and 92.5 ± 5.0 & 86.6 ± 5.4 post‐operation (P < 0.05); Patients in the periportal group, the mHHS and HOS‐ADL scores improvement were respectively 69.9 ± 15.8, 68.1 ± 15.0 pre‐operation, and 90.1 ± 9.3 & 86.7 ± 7.9 post‐operation (P < 0.05).The differences were statistically significant. Six months after operation, MRI showed that 23 patients with periportal capsulotomy, the capsule have healed, without other complications. Three of the ten patients with interportal capsulotomy were healed and seven were not.

Conclusion

Interportal and periportal capsulotomy had good outcomes. The technique of periportal capsulotomy had little damage to the joint capsule. Although the capsule did not close, the capsule healed well in postoperative follow‐up. The nonunion rate of the joint capsule was high in the interportal capsulotomy without close the capsule.

Sensory Innervation of the Hip Joint and Referred Pain: A Systematic Review of the Literature

OBJECTIVES

The aim of this literature review was to establish consensus with respect to the anatomic features of the articular branches innervating the hip joint and the distribution of sensory receptors within its capsule.

METHODS

Five electronic databases were queried, with the search encompassing articles published between January 1945 and June 2019. Twenty-one original articles providing a detailed description of sensory receptors around the hip joint capsule (n=13) and its articular branches (n=8) were reviewed.

RESULTS

The superior portions of the anterior capsule and the labrum were found to be the area of densest nociceptive innervation. Similar to the distribution of nociceptors, mechanoreceptor density was found to be higher anteriorly than posteriorly. Hip joint capsular innervation was found to consistently involve the femoral and obturator nerves, which supply the anterior capsule, and the nerve to the quadratus femoris, which supplies the posterior capsule. The femoral, obturator, and superior gluteal nerves supply articular branches to the most nociceptor-rich region of the hip capsule.

CONCLUSIONS

The femoral and obturator nerves and the nerve to the quadratus femoris were found to consistently supply articular branches to both the anterior and posterior capsule of the hip joint. The anterior capsule, primarily supplied by the femoral and obturator nerves, and the superior labrum appear to be the primary pain generators of the hip joint, given their higher density of nociceptors and mechanoreceptors.

LEVEL OF EVIDENCE

Anatomy study, literature review.

A systematic review and meta-analysis of the hip capsule innervation and its clinical implications

Detailed understanding of the innervation of the hip capsule (HC) helps inform surgeons’ and anaesthetists’ clinical practice. Post-interventional pain following radiofrequency nerve ablation (RFA) and dislocation following total hip arthroplasty (THA) remain poorly understood, highlighting the need for more knowledge on the topic. This systematic review and meta-analysis focuses on gross anatomical studies investigating HC innervation. The main outcomes were defined as the prevalence, course, density and distribution of the nerves innervating the HC and changes according to demographic variables. HC innervation is highly variable; its primary nerve supply seems to be from the nerve to quadratus femoris and obturator nerve. Many articular branches originated from muscular branches of the lumbosacral plexus. It remains unclear whether demographic or anthropometric variables may help predict potential differences in HC innervation. Consequently, primary targets for RFA should be the anterior inferomedial aspect of the HC. For THA performed on non-risk patients, the posterior approach with capsular repair appears to be most appropriate with the lowest risk of articular nerve damage. Care should also be taken to avoid damaging vessels and muscles of the hip joint. Further investigation is required to form a coherent map of HC innervation, utilizing combined gross and histological investigation.

Healthy Hip Joints Have Different Macroscopic and Microscopic Capsular Nerve Architecture Compared With Hips With Osteoarthritis, Femoroacetabular Impingement Syndrome, and Developmental Dysplasia of the Hip: A Systematic Review

Purpose

To perform a systematic review to identify macroscopic and microscopic patterns and differences in hip capsule innervation between normal hips and hips with osteoarthritis (OA), femoroacetabular impingement (FAI) syndrome, and developmental dysplasia of the hip (DDH).

Methods

A systematic review was performed using Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Multiple databases were searched for both clinical and basic science laboratory studies on hip capsule innervation. Non-innervation capsule and non-human animal studies were excluded. Macroscopic and microscopic differences in capsular innervation between normal hips, and hips with OA, FAI, and DDH were analyzed. Methodological quality assessment of all studies included in this review was completed using the Methodological Index for Non-randomized Studies.

Results

Ten articles were analyzed (263 specimens; 211 patients, 52 cadavers; mean Methodological Index for Non-randomized Studies 10/16). The hip capsule is innervated by the sciatic and superior gluteal nerves posterosuperiorly, nerve to quadratus femoris and inferior gluteal nerve posteroinferiorly, and femoral and obturator nerves anteriorly. The anterior-superior capsule between 1:00 and 2:30 o’clock on a right hip is a safe internervous zone. The superolateral capsule has the greatest density of mechanoreceptors and sensory fibers. OA is associated with a greater expression of nerve fibers compared with normal hips but does not correlate with pain or disability. No significant differences were found in nerve fiber expression among patients with DDH, FAI, or normal hips. A negative correlation is seen with aging and pain fiber expression.

Conclusions

The hip capsule has a complex macroscopic and microscopic innervation pattern with varying nerve fiber expression from at least 6 separate peripheral nerves. OA is associated with a greater expression of nerve fibers, although nerve fiber expression does not correlate with painful pathology.

Level of Evidence

IV, Systematic review of level I-IV studies.

Revision of Failed Open Reduction of Developmental Dysplasia of the Hip

Background

The most common causes of re-dislocation after open reduction are inadequate exposure and failure to release the obstructing soft tissues inside and around the hip.

Methods

This clinical study included 33 consecutive children (34 hips) who underwent a revision surgery after failed open reduction of developmental dysplasia of the hip (DDH).

Results

According to the McKay clinical criteria, the results were good in 28 cases (82.4%), fair in 4 cases (11.8%), and poor in 2 cases with re-dislocation (5.9%). Radiological results according to the modified Severin criteria were as follows: 28 hips (82.4%) were identified as category 2 (good), 4 hips (11.8%) category 4 (fair), and 2 hips (5.9%) category 5 (poor).

Conclusions

Revision surgery for DDH is demanding and the long-term consequences are usually serious, but stable, concentric reduction should be obtained either at the first or second open reduction by addressing the causes of failure. Failed acetabulum remodeling and technical errors with inadequate soft-tissue release were the most common causes of failure in the primary operation. Based on the results, the outcome of revision surgery after failed open reduction for DDH was good.

Innervation of the hip joint capsular complex: A systematic review of histological and immunohistochemical studies and their clinical implications for contemporary treatment strategies in total hip arthroplasty

The hip joint capsule contributes to the stability of the hip joint and lower extremity, yet this structure is incised and often removed during total hip arthroplasty (THA). Increasing incidence of osteoarthritis is accompanied by a dramatic rise in THAs over the last few decades. Consequently, to improve this treatment, THA with capsular repair has evolved. This partial restoration of physiological hip stability has resulted in a substantial reduction in post-operative dislocation rates compared to conventional THA without capsular repair. A further reason for the success of this procedure is thought to be the preservation of the innervation of the capsule. A systematic review of studies investigating the innervation of the hip joint capsular complex and pseudocapsule with histological techniques was performed, as this is not well established. The literature was sought from databases Amed, Embase and Medline via OVID, PubMed, ScienceDirect, Scopus and Web of Science; excluding articles without a histological component and those involving animals. A total of 21 articles on the topic were identified. The literature indicates two primary outcomes and potential clinical implications of the innervation of the capsule. Firstly, a role in the mechanics of the hip joint, as mechanoreceptors may be present in the capsule. However, the nomenclature used to describe the distribution of the innervation is inconsistent. Furthermore, the current literature is unable to reliably confirm the proprioceptive role of the capsule, as no immunohistochemical study to date has reported type I-III mechanoreceptors in the capsule. Secondly, the capsule may play a role in pain perception, as the density of innervation appears to be altered in painful individuals. Also, increasing age may indicate requirements for different strategies to surgically manage the hip capsule. However, this requires further study, as well as the role of innervation according to sex, specific pathology and other morphometric variables. Increased understanding may highlight the requirement for capsular repair following THA, how this technique may be developed and the contribution of the capsule to joint function and stability.

Intraneural Ganglion Cyst of the Sciatic Nerve Treated Using Arthroscopic Hip Surgery: A Case Report

This is a rare case of sciatic neuropathy in a 46-year-old man secondary to an intraneural ganglion cyst from the hip joint extending upward to the lumbar plexus and the L5 nerve root. Magnetic resonance neurography showed that the joint fluid passed through a labral tear and extended rostrally along the articular branch and the peroneal portion of the sciatic nerve to near the L5 nerve root. The condition was treated by arthroscopic disruption of the joint connection to the nerve with resolution of the intraneural cyst and partial neurological recovery.

Extracapsular local infiltration analgesia in hip arthroscopy patients: a randomized, prospective study

Hip arthroscopy patients can experience significant post-operative pain. Many strategies to combat this pain have been explored including nerve blocks, which can be costly. An alternative option for pain management is local infiltration analgesia (LIA) which has been studied in hip and knee arthroplasty, but its ability to decrease pain in the setting of hip arthroscopy remains uncertain. A prospective randomized controlled trial of 74 patients who underwent hip arthroscopy at a single medical center was performed. Thirty-seven patients received a 20-ml extracapsular injection of 0.25% bupivacaine-epinephrine under direct arthroscopic visualization after capsular closure while 37 from the control group received no injection. Primary outcome measures were both maximum and discharge numeric rating scale (NRS) pain scores while in the post-anesthesia care unit (PACU). The LIA group had a statistically significant decrease in the maximum PACU NRS score (6.16 versus 7.35, P = 0.009), however this did not reach the level of minimal clinically important difference of 1.5. There was an insignificant difference in discharge PACU pain scores. This is the first randomized controlled trial studying extracapsular LIA in hip arthroscopy. While LIA offers an uncomplicated and low-cost approach to post-operative pain management, this specific technique did not reduce pain to a clinically significant level.

Spread of injectate around hip articular sensory branches of the femoral nerve in cadavers

BACKGROUND

Anatomical knowledge dictates that regional anaesthesia after total hip arthroplasty requires blockade of the hip articular branches of the femoral and obturator nerves. A direct femoral nerve block increases the risk of fall and impedes mobilisation. We propose a selective nerve block of the hip articular branches of the femoral nerve by an ultrasound-guided injection in the plane between the iliopsoas muscle and the iliofemoral ligament (the iliopsoas plane). The aim of this study was to assess whether dye injected in the iliopsoas plane spreads to all hip articular branches of the femoral nerve.

METHODS

Fifteen cadaver sides were injected with 5 mL dye in the iliopsoas plane guided by ultrasound. Dissection was performed to verify the spread of injectate around the hip articular branches of the femoral nerve.

RESULTS

In 10 dissections (67% [95% confidence interval: 38-88%]), the injectate was contained in the iliopsoas plane staining all hip articular branches of the femoral nerve without spread to motor branches. In four dissections (27% [8-55%]), the injection was unintentionally made within the iliopectineal bursa resulting in secondary spread. In one dissection (7% [0.2-32%]) adhesions partially obstructed the spread of dye.

CONCLUSION

An injection of 5 mL in the iliopsoas plane spreads around all hip articular branches of the femoral nerve in 10 of 15 cadaver sides. If these findings translate to living humans, injection of local anaesthetic into the iliopsoas plane could generate a selective sensory nerve block of the articular branches of the femoral nerve without motor blockade.

Synovial Ganglion of the Hip as a Rare Cause of L5 Radiculopathy: A Case Report

CASE

We report a rare case of a dorsal synovial ganglion of the left hip causing L5 radiculopathy in a 48-year-old woman. After a 12-month history of intermittent pain in the groin, left buttock, and left lower limb, magnetic resonance imaging (MRI) of the pelvis revealed a 10-cm-long cystic ganglion. The lesion originated from the posterior aspect of the hip joint capsule and extended through the sciatic notch toward the L5 nerve root, causing severe nerve compression. Open resection of the ganglion via surgical hip subluxation was performed.

CONCLUSION

Combined presentation of symptoms attributable to intrinsic hip disease and peripheral radiculopathy should raise suspicion for a shared cause of these entities.

Extracapsular local infiltration analgesia in hip arthroscopy: a retrospective study

Many hip arthroscopy patients experience significant pain in the immediate postoperative period. Although peripheral nerve blocks have demonstrated efficacy in alleviating some of this pain, they come with significant costs. Local infiltration analgesia (LIA) may be a significantly cheaper and efficacious treatment modality. Although LIA has been well studied in hip and knee arthroplasty, its efficacy in hip arthroscopy is unclear. The purpose of this retrospective study is to determine the efficacy of a single extracapsular injection of bupivacaine-epinephrine during hip arthroscopy in reducing the rate of elective postoperative femoral nerve blocks. A retrospective review of 100 consecutive patients who underwent primary hip arthroscopy at a single medical center was performed. The control group consisted of 50 patients before the implementation of the current LIA protocol, whereas another 50 patients received a 20-ml extracapsular injection of 0.25% bupivacaine-epinephrine under direct arthroscopic visualization after capsular closure. In the post-anesthesia care unit (PACU), patients were offered a femoral nerve block for uncontrolled pain. The rate of femoral nerve block, and total opioid consumption, was compared between groups. The proportion of patients receiving elective femoral nerve blocks was significantly less in the LIA group (34%) as compared with the control group (56%; P = 0.027). There was no significant difference in total PACU opioid consumption between groups (P = 0.740). The decreased utilization of postoperative nerve blocks observed in the LIA group suggests that LIA may improve postoperative pain management and should be considered as a potentially cost-effective tool in pain management in hip arthroscopy patients. Level of Evidence: III.

Arthroscopic reduction and internal fixation of femoral head fractures

Displaced femoral head fractures often require open reduction and internal fixation. This article describes 3 cases of displaced large-fragment femoral head fractures (OTA 31-C1.3) that were treated by arthroscopic reduction and internal fixation, which was accomplished using an anterolateral viewing portal, an anterior portal, and an accessory distal anterior working portal. By 3 months postoperatively, all 3 patients had returned to full function. Therefore, we conclude that an arthroscopic approach results in stable fixation and early joint motion, thereby effectively treating displaced femoral head fractures in a minimally invasive manner.

Standard Transgluteal versus Minimal Invasive Anterior Approach in hip Arthroplasty: A Prospective, Consecutive Cohort Study

A minimally invasive anterior approach (MIS) was compared to a standard lateral approach in primary total hip arthroplasty. Clinical and radiological outcomes were analyzed 6 weeks, 12 weeks, one year and two years after surgery. The duration of surgery was longer, mobility one week after surgery was better and time of hospitalization was shorter for minimally invasive-treated patients. They had less pain during movement, limping, better Harris Hip Score and satisfaction after 6 weeks, which remained after 12 weeks and 1 year, but not after two years. There were two deep infections in the MIS group. Radiological results were not affected. The infections might be a point of concern, but there were no other disadvantages of the MIS approach. In fact, early rehabilitation was facilitated and clinical results were improved. Our results encourage the continuous use of the MIS anterior approach instead of the lateral approach.

MAASH Technique for Total Hip Arthroplasty: A Capsular Work

BACKGROUND

Dislocation and leg length discrepancy are major complications following total hip arthroplasty (THA). Many surgical approaches for THA have been described, but none suggest a capsular incision that assures good exposure while maintaining adequate capsule integrity in closure.

PURPOSES

Modified anterolateral approach for stable hip (MAASH) is a modification of the classical Hardinge approach, but specifically preserves the anterior iliofemoral lateral ligament and pubofemoral ligament excising the "weak area" of the capsule, in the so called "internervous safe zone" and introducing the "box concept" for the anterior approach to the hip. This is the main difference of the MAASH approach. This technique can be used as a standard for all THA standard models, but we introduce new devices to make it easier.

METHODS

From November 2007 to May 2012, data were collected for this observational retrospective consecutive case study. We report the results of 100 THA cases corresponding to the development curve of this new concept in THA technique.

RESULTS

MAASH technique offers to hip surgeons, a reliable and reproducible THA anterolateral technique assuring accurate reconstruction of leg length and a low rate of dislocation. Only one dislocation and six major complications are reported, but most of them occurred at the early stages of technique development.

CONCLUSION

MAASH technique proposes a novel concept on working with the anterior capsule of the hip for the anterolateral approach in total hip arthroplasty, as well as for hemiarthroplasty in the elderly population with high dislocation risk factors. MAASH offers maximal stability and the ability to restore leg length accurately.

Sources of sensory innervation of the hip joint capsule in the rabbit - a retrograde tracing study

The aim of the study was to investigate the sensory innervation of the hip joint capsule in the rabbit. Individual animals were injected with retrograde fluorescent tracer Fast Blue (FB) into the lateral aspect of the left hip joint capsule (group LAT, n = 5) or into the medial aspect of the hip joint capsule (group MED, n = 5), respectively. FB-positive (FB+) neurons were found within ipsilateral lumbar (L) and sacral (S) dorsal root ganglia (DRG) from L7 to S2 (group LAT) and from L6 to S4 (group MED). They were round or oval in shape with a diameter of 20-90 μm. The neurons were evenly distributed throughout the ganglia. The average number of FB+ neurons was 16 ± 2.8 and 27.6 ± 3.5 in rabbits from LAT and MED, respectively. The largest average number of FB+ neurons in animals of group LAT was found within the S1 DRG (8 ± 1.7), while S2 ganglion contained the smallest number of the neurons (3.6 ± 1). In the L7 DRG, the average number of FB+ neurons was 6.2 ± 1.6. In rabbits of MED group, the largest number of FB+ neurons was found within the S1 DRG (13.4 ± 4), while the smallest one was found within the S3 ganglion (1.4 ± 0.4). In L6, L7, S2 and S4 ganglia, the number of retrogradely labelled neurons amounted to 1.6 ± 0.5, 4 ± 1.5, 4.4 ± 1.5 and 2.8 ± 1.7, respectively. The data obtained can be very useful for further investigations regarding the efficacy of denervation in the therapy of hip joint disorders in rabbits.

The characteristics of the mechanoreceptors of the hip with arthrosis

Mechanoreceptors have been extensively studied in different joints and distinct signals that convey proprioceptive information to the cortex. Several clinical reports have established a link between the number of mechanoreceptors and a deficient proprioceptive system; however, little or no literature suggest concentration of mechanoreceptors might be affected by hip arthrosis. The purpose of this study is first to determine the existence of mechanoreceptors and free nerve endings in the hip joint and to distinguish between their conditions: those with arthrosis and without arthrosis. Samples of 45 male hips were analyzed: 30 taken from patients with arthrosis that were submitted to total arthroplasty and 15 taken from male cadavers without arthrosis. The patients' ages ranged from 38 to75 years (average 56.5) and the cadavers' ages ranged from 21 to 50 years (average 35.5). The capsule, labrum, and femoral head ligament tissues were obtained during the arthroplasty procedure from 30 patients with arthrosis and from 15 male cadavers. The tissue was cut into fragments of around 3 mm. Each fragment was then immediately stained with gold chloride 1% solution and divided into sections of 6 μm thickness. The Mann-Whitney test was used for two groups and the ANOVA, Friedman and Kruskal-Wallis tests for more than two groups. Results show the mechanoreceptors (Pacini, Ruffini and Golgi corpuscles) and free nerve endings are present in the capsule, femoral head ligament, and labrum of the hip joint. When all the densities of the nerve endings were examined with regard to those with arthrosis and those without arthrosis, the mechanoreceptors of cadavers without arthrosis were found to be more pronounced and an increase in free nerve endings could be observed (p = 0.0082). Further studies, especially electrophysiological studies, need to be carried out to clarify the functions of the mechanoreceptors in the joints.

Reduced postoperative pain in total hip arthroplasty after minimal-invasive anterior approach

PURPOSE

The development of minimal-incision techniques for total hip replacement with preservation of soft tissue is generally associated with faster rehabilitation, reduction of postoperative pain and increased patient comfort. The aim of this study was to compare a minimal-incision anterior approach with a transgluteal lateral technique for hip replacement surgery with respect to postoperative pain, consumption of rescue medication, length of hospital stay and time to reach a defined range of motion.

METHODS

In this retrospective cohort study we investigated 100 patients with a minimal-incision anterior approach (group I) and 100 patients with a transgluteal lateral approach (group II) retrospectively undergoing unilateral hip replacement. The study variables were pain at rest and during physiotherapy, amount of rescue medication, the time to reach a defined flexion and time in hospital.

RESULTS

The patients of group I consumed less rescue medication (19.6 ± 6.9 mg vs. 23.6 ± 11.3 mg;  p = 0.005) and experienced less pain on the day of surgery (1.3 ± 1 vs. 2.3 ± 1.3, p = 0.0001) and the first postoperative day (0.41 ± 0.8 vs. 0.66 ± 1.1, p = 0.036). The time to reach the defined range of motion (6.4 ± 2 days vs. 7.4 ± 2.1 days; p = 0.001) and the length of hospital stay were shorter (10.2 ± 1.9 days vs. 13.4 ± 1.6 days; p = 0.0001) for group I. However, pain during physiotherapy was higher on the third and sixth through ninth days after surgery in comparison to group II (p = 0.001-0.013).

CONCLUSION

The implantation of a hip prosthesis through a minimal-incision anterior approach is successful in reducing postoperative pain and consumption of pain medication. Time to recovery and length of hospital stay are also influenced positively. Pain increases during physiotherapy, and may be mitigated by adopting limited weight bearing during the early postoperative period.

Intraneural ganglia in the hip and pelvic region. Clinical article

OBJECT

The authors describe their experience in a series of cases of intraneural ganglia within the hip and pelvic regions, and explain the mechanism of formation and propagation of this pathological entity.

METHODS

Five patients with 6 intraneural ganglia are presented. Four patients presented with symptomatic intraneural ganglia in the buttock and pelvis affecting the sciatic and lumbosacral plexus elements. An asymptomatic cyst affecting the opposite sciatic nerve was found on MR imaging in 1 patient. The fifth patient, previously reported on by another group, had an obturator intraneural ganglion that the authors reinterpreted.

RESULTS

All 5 intraneural ganglia affecting the sciatic and lumbosacral plexus elements were found to have a joint connection to the posteromedial aspect of the hip joint; the obturator intraneural cyst had a joint connection to the anteromedial aspect of the hip joint. In all cases, initial review of the MR images led to their misinterpretation.

CONCLUSIONS

To the authors' knowledge, these are the first cases of intraneural ganglia demonstrated to have a connection to the hip joint. This finding at a rare site provides further evidence for the unifying articular (synovial) theory for the formation of intraneural ganglia and reveals a shared mechanism for their propagation. Furthermore, understanding the pathogenesis of these lesions provides insight into their successful treatment and their recurrence.

A rare fracture, an even rarer treatment: the arthroscopic reduction and internal fixation of an isolated femoral head fracture

This case report describes the first documented arthroscopic reduction and internal fixation of a rare isolated femoral head fracture without associated dislocation. A large suprafoveal osteochondral fracture was arthroscopically reduced by use of crossover techniques gained from experience performing arthroscopic femoroacetabular impingement surgery. An innovative "chopstick" maneuver was used to rotate the mobilized osteochondral fragment into anatomic position, followed by arthroscopic Herbert screw fixation. Relevant surgical techniques and clinical outcome are presented. Although this case shows arthroscopic osteosynthesis for a rare fracture, the techniques described herein may permit broader arthroscopic applications. As hip arthroscopy evolves, the role of arthroscopic surgery in the traumatized hip may expand beyond diagnostic arthroscopy and foreign/loose body removal. An anatomic reduction with stable internal fixation permitting early joint motion trumps the ability to perform outpatient arthroscopic procedures. However, if the equivalent procedure can indeed be accomplished in a safe and minimally invasive manner, one can envision a future expansion of the role of hip arthroscopic surgery in fracture management.

Acute iatrogenic dislocation following hip impingement arthroscopic surgery

This is the first case report of an iatrogenic anterior hip dislocation after arthroscopic surgery for femoroacetabular impingement with over 1 year of follow-up. This case report describes the clinical course of a patient with symptomatic cam-pincer femoroacetabular impingement. She underwent arthroscopic rim trimming, labral debridement after a failed attempt at labral refixation from suture cut-through, and femoral head-neck resection osteoplasty. The procedure involved supranormal hip distraction for extraction of an iatrogenic loose body (detached metallic radiofrequency probe tip). The patient had an anterior hip dislocation in the recovery room. Immediate closed reduction under general anesthesia and bracing were performed but failed despite the ability to obtain a concentric but grossly unstable reduction. After 3 failed attempts, a mini-open capsulorrhaphy was performed that successfully restored stability. Her postoperative management and outcome are presented. All of the major static stabilizers of the hip (osseous, labral, and capsuloligamentous) were surgically altered, and a multifactorial causation is proposed. Lessons learned are discussed in hopes of minimizing the occurrence of this rare but dramatic complication.