Background: The jackling position within rugby has not been previously described as a mechanism for proximal hamstring injuries. Hypothesis: Acute surgical repair of proximal hamstring avulsion injuries sustained from the jackling contact position enables a return to a previous level of sporting activity with low risk of recurrence. Study Design: Case series; Level of evidence, 4. Methods: This study included 54 professional rugby players (mean age, 26 ± 4.8 years) who underwent acute primary surgical repair of complete, proximal hamstring avulsion injuries. The mean follow-up time was 17 months (range, 12-24 months). Mean isometric hamstring strength and function testing was performed at 3 months and 1 year after repair. Results: Of the 54 players, 51 (94.4%) returned to their preinjury level of sporting activity. The mean time from surgical repair to full sporting activity was 7 months (range, 4-12 months). No patients had recurrence of the primary injury. At 1 year postoperatively, patients had significantly restored mean isometric hamstring muscle strength when compared with the uninjured leg at 0° (98.4% ± 2.8%), 15° (95.9% ± 2.9%), and 45° (92.9% ± 4.1%); improved Lower Extremity Functional Score (78.0 ± 2.0); and improved Marx activity rating score (14.3 ± 1.5) ( P < .001 for all). Conclusion: Acute surgical repair of proximal hamstring avulsion injuries caused by the contact jackling position produced a high return to preinjury level of sporting activity, increased muscle strength, and improved functional outcome scores, with a low risk of recurrence at short-term follow-up.

We had previously reported on early outcomes on a new fluted, titanium, monobloc stem with a three degree taper that has been designed for challenging femoral reconstruction in the setting of extensive bone loss. The aim of this study was to report its mid-term clinical and radiographic outcomes.This is a retrospective review of prospectively collected data carried out at a single institution between Jan 2017 and Dec 2019. 85 femoral revisions were performed using a new tapered, fluted, titanium, monobloc (TFTM) revision stem. Complications, clinical and radiographic data were obtained from medical records and a locally maintained database. Clinical outcomes were assessed using the Oxford Hip Score (OHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). All post-operative radiographs were analysed for subsidence, osteolysis and femoral cortical bone remodelling.Mean follow-up was 60 months (range 28–84 months). Subsidence of 1.2 mm was noted in one patient. No cases of clinically significant subsidence (10 mm) were observed. At final follow-up, a statistically significant improvement was noted in functional outcome scores. The mean OHS preoperatively and at final follow-up were 24 (SD 13) and 42 (SD15). p = 0.04 mean difference 18 (95% CI 15–22). The mean WOMAC scores preoperatively and at final follow-up were 62 (SD23) and 88 (SD7) respectively (p < 0.001, mean difference 26; 95% CI 21–34). No stem fractures were noted within the follow-up period. Two patients had revision of the stem's one for infection and another for persistent pain.Positive mid-term clinical and radiological outcomes have been observed with this tapered, fluted, titanium, monobloc stem. Based on these results, this implant may be considered as a viable option in the majority of uncemented femoral revisions.

Muscle injury classification systems for hamstring injuries have evolved to use anatomy and imaging information to aid management and prognosis. However, classification systems lack reliability and validity data and are not specific to individual hamstring muscles, potentially missing parameters vital for sport-specific and activity-specific decision making. A narrative evidence review was conducted followed by a modified Delphi study to build an international consensus on best-practice decision-making for the classification of hamstring injuries. This comprised a digital information gathering survey to a cohort of 46 international hamstring experts (sports medicine physicians, physiotherapists, surgeons, trainers and sports scientists) who were also invited to a face-to-face consensus group meeting in London . Fifteen of these expert clinicians attended to synthesise and refine statements around the management of hamstring injury. A second digital survey was sent to a wider group of 112 international experts. Acceptance was set at 70% agreement. Rounds 1 and 2 survey response rates were 35/46 (76%) and 99/112 (88.4%) of experts responding. Most commonly, experts used the British Athletics Muscle Injury Classification (BAMIC) (58%), Munich (12%) and Barcelona (6%) classification systems for hamstring injury. Issues identified to advance imaging classifications systems include: detailing individual hamstring muscles, establishing optimal use of imaging in diagnosis and classification, and testing the validity and reliability of classification systems. The most used hamstring injury classification system is the BAMIC. This consensus panel recommends hamstring injury classification systems evolve to integrate imaging and clinical parameters around: individual muscles, injury mechanism, sporting demand, functional criteria and patient-reported outcome measures. More research is needed on surgical referral and effectiveness criteria, and validity and reliability of classification systems to guide management.

Hamstring injuries (HSIs) are the most common athletic injury in running and pivoting sports, but despite large amounts of research, injury rates have not declined in the last 2 decades. HSI often recur and many areas are lacking evidence and guidance for optimal rehabilitation. This study aimed to develop an international expert consensus for the management of HSI. A modified Delphi methodology and consensus process was used with an international expert panel, involving two rounds of online questionnaires and an intermediate round involving a consensus meeting. The initial information gathering round questionnaire was sent to 46 international experts, which comprised open-ended questions covering decision-making domains in HSI. Thematic analysis of responses outlined key domains, which were evaluated by a smaller international subgroup (n=15), comprising clinical academic sports medicine physicians, physiotherapists and orthopaedic surgeons in a consensus meeting. After group discussion around each domain, a series of consensus statements were prepared, debated and refined. A round 2 questionnaire was sent to 112 international hamstring experts to vote on these statements and determine level of agreement. Consensus threshold was set a priori at 70%. Expert response rates were 35/46 (76%) (first round), 15/35 (attendees/invitees to meeting day) and 99/112 (88.2%) for final survey round. Statements on rehabilitation reaching consensus centred around: exercise selection and dosage (78.8%–96.3% agreement), impact of the kinetic chain (95%), criteria to progress exercise (73%–92.7%), running and sprinting (83%–100%) in rehabilitation and criteria for return to sport (RTS) (78.3%–98.3%). Benchmarks for flexibility (40%) and strength (66.1%) and adjuncts to rehabilitation (68.9%) did not reach agreement. This consensus panel recommends individualised rehabilitation based on the athlete, sporting demands, involved muscle(s) and injury type and severity (89.8%). Early-stage rehab should avoid high strain loads and rates. Loading is important but with less consensus on optimum progression and dosage. This panel recommends rehabilitation progress based on capacity and symptoms, with pain thresholds dependent on activity, except pain-free criteria supported for sprinting (85.5%). Experts focus on the demands and capacity required for match play when deciding the rehabilitation end goal and timing of RTS (89.8%). The expert panellists in this study followed evidence on aspects of rehabilitation after HSI, suggesting rehabilitation prescription should be individualised, but clarified areas where evidence was lacking. Additional research is required to determine the optimal load dose, timing and criteria for HSI rehabilitation and the monitoring and testing metrics to determine safe rapid progression in rehabilitation and safe RTS. Further research would benefit optimising: prescription of running and sprinting, the application of adjuncts in rehabilitation and treatment of kinetic chain HSI factors.

The key indications for surgical repair of hamstring injuries (HSIs) remain unclear in the literature due to a lack of high-level evidence and expert knowledge. The 2020 London International Hamstring Consensus meeting aimed to highlight clear surgical indications and to create a foundation for future research. A literature review was conducted followed by a modified Delphi process, with an international expert panel. Purposive sampling was used with two rounds of online questionnaires and an intermediate round involving a consensus meeting. The initial information gathering (round 1) questionnaire was sent to 46 international experts, which comprised open-ended questions covering decision-making domains in HSI. Thematic analysis of responses outlined key domains, which were evaluated by a smaller international subgroup (n=15) comprising clinical academic sports medicine physicians, physiotherapists and orthopaedic surgeons in a consensus meeting. After group discussion of each domain, a series of consensus statements were prepared, debated and refined. A round 2 questionnaire was sent to 112 international hamstring experts to vote on these statements and determine level of agreement. The consensus threshold was set a priori at 70% agreement. Rounds 1 and 2 survey respondents were 35/46 (76%) and 99/112 (88.4%), respectively. The consensus group agreed that the indications for operative intervention included: gapping at the zone of tendinous injury (87.2% agreement) and loss of tension (70.7%); symptomatic displaced bony avulsions (72.8%); and proximal free tendon injuries with functional compromise refractory to non-operative treatment (72.2%). Other important considerations for operative intervention included: the demands of the athlete/patient and the expected functional outcome (87.1%) based on the anatomy of the injury; the risk of functional loss/performance deficit with non-operative management (72.2%); and the capacity to restore anatomy and function (87.1%). Further research is needed to determine whether surgery can reduce the risk of reinjury as consensus was not reached within the whole group (48.2%) but was agreed by surgeons (70%) in the cohort. The consensus group did not support the use of corticosteroids or endoscopic surgery without further evidence. These guidelines will help standardise treatment of HSIs, specifically the indications and decision-making for surgical intervention.

Background: The multidisciplinary consensus panel included 14 International specialists on the management of hamstring injuries.

Background: The Jackling position within rugby has not been previously described as a mechanism for proximal hamstring injuries. Methods: This prospective single surgeon study included 54 professional rugby players (mean age 26±4.8 years) undergoing acute primary surgical repair of complete, proximal hamstring avulsion injuries confirmed on preoperative magnetic resonance imaging. All study patients underwent a standardised postoperative rehabilitation programme. Predefined outcomes were recorded at regular intervals. Mean follow-up time was 17 months (range, 12 to 24 months) from date of surgery. Results: A total of 51 patients (94.4%) returned to their pre-injury level of sporting activity. Mean time from surgical repair to full sporting activity was 7 months (range, 4 to 12 months). Zero patients had recurrence of the primary injury. At 1 year after surgery compared to 3 months after surgery, patients had increased mean isometric hamstring muscle strength at 0° (98.4%±2.8% vs. 88.1%±5.4%, P<0.001), 15° (95.9%±2.9% vs. 88.2%±8.1%, P<0.001) and 45° (92.9%±4.1% vs. 76.8%±9.7%, P<0.001), higher mean lower extremity functional scores (77.0±2.3 vs. 64.5±4.5, P<0.001), and improved Marx activity rating scores (14.3±1.5 vs. 10.7±2.6, P<0.001). Conclusions: Acute surgical repair of proximal hamstring avulsion injuries caused by the contact Jackling position produces high patient satisfaction, high return to preinjury level of sporting activity, with low risk of recurrence at short-term follow up.

BACKGROUND:Understanding the optimal management of distal semitendinosus hamstring injuries is critical for reducing pain, restoring preinjury function, maintaining knee stability, improving hamstring muscle strength, and minimizing the risk of complications and recurrence. To our knowledge, the outcomes of surgical tenodesis for distal semitendinosus hamstring injuries have not been previously reported. HYPOTHESIS:Surgical tenodesis for injuries of the semitendinosus would enable return to preinjury level of sport with low risk of recurrence. STUDY DESIGN:Case series; Level of evidence, 4. METHODS:This prospective single-surgeon study included 13 professional athletes (12 men, 1 woman; mean age, 32 ± 8.2 years; mean body mass index, 26.7 ± 3.9 kg/m2) undergoing treatment for distal semitendinosus hamstring injuries with primary tenodesis to the distal semimembranosus. Indications for surgical tenodesis included distal semitendinosus tendon avulsion injury (n = 8) or residual tendon instability and hamstring weakness after semitendinosus graft harvest for anterior cruciate ligament reconstruction (n = 5). All study patients underwent a standardized postoperative rehabilitation program. The primary outcome was defined as time for return to sporting activity. Secondary outcomes were patient satisfaction, injury recurrence, and complications. The mean follow-up time was 17 months (range, 12-24 months) from date of surgery. RESULTS:All study patients returned to their preinjury level of sporting activity. The mean time from the surgical intervention to return to full sporting activity was 15 ± 4.6 weeks. At 1-year follow-up, all study patients were still participating at their preinjury level of sporting activity, and 12 patients (92%) were very satisfied and 1 patient (8%) was satisfied about the outcomes of their surgery. No study patients had recurrence of the primary injury. No surgical complications, injury recurrence, or reoperations were observed within the follow-up period. CONCLUSION:Early return to sporting activity was seen after surgical tenodesis for distal semitendinosus hamstring injuries after acute trauma or residual symptoms following previous hamstring graft harvest, with high levels of patient satisfaction and low risk of recurrence at short-term follow-up.

Aims Graft infection following anterior cruciate ligament reconstruction (ACLR) may lead to septic arthritis requiring multiple irrigation and debridement procedures, staged revision operations, and prolonged courses of antibiotics. To our knowledge, there are no previous studies reporting on how gentamicin pre-soaking of hamstring grafts influences infection rates following ACLR. We set out to examine this in our study accordingly. Methods This retrospective study included 2,000 patients (1,156 males and 844 females) who underwent primary ACLR with hamstring autografts between 2007 to 2017. This included 1,063 patients who received pre-soaked saline hamstring grafts for ACLR followed by 937 patients who received pre-soaked gentamicin hamstring grafts for ACLR. All operative procedures were completed by a single surgeon using a standardized surgical technique. Medical notes were reviewed and data relating to the following outcomes recorded: postoperative infection, clinical progress, causative organisms, management received, and outcomes. Results Superficial wound infection developed in 14 patients (1.31 %) receiving pre-saline soaked hamstring grafts compared to 13 patients (1.38 %) receiving pre-gentamicin soaked hamstring grafts, and this finding was not statistically significant (p = 0.692). All superficial wound infections were treated with oral antibiotics with no further complications. There were no recorded cases of septic arthritis in patients receiving pre-gentamicin soaked grafts compared to nine patients (0.85%) receiving pre-saline soaked grafts, which was statistically significant (p = 0.004). Conclusion Pre-soaking hamstring autographs in gentamicin does not affect superficial infection rates but does reduce deep intra-articular infection rates compared to pre-soaking hamstring grafts in saline alone. These findings suggest that pre-soaking hamstring autografts in gentamicin provides an effective surgical technique for reducing intra-articular infection rates following ACLR.

ABSTRACT:Coronavirus disease 2019 (COVID-19) was declared a pandemic by the World Health Organization on March 11, 2020. By mid-March, London had emerged as the epicenter in the United Kingdom, accounting for 45% of the COVID-19-related mortality. A cancer COVID-19-free "cold hub," through National Health Service partnership with independent institutions, was established to maintain a throughput of surgical oncology patients with an accessible triage system for oncologic specialties. The high population density, commuter volume, and rising COVID-19 incidence heightened the challenge of segregating a vulnerable population that was already at high risk for surgical morbidity and mortality.The aim of this review is to report the experience of developing a multicenter COVID-19-free cold hub with the aim of providing safe surgery for surgical oncology patients. We discuss the timeline, structure, and infection control policy and suggest practical points that may guide other health care systems.The surgical oncology hub treated 1542 patients between March 1 and July 1, 2020. There were no cases of COVID-19-related mortality in a 30-day follow-up. Key strategies for the restructuring of the cancer service included the following: (1) formation of an accessible referral pathway, (2) creation and structuring of cold hub hospitals, (3) development of protocols for infection control and preoperative testing, (4) rapid reorganization of services based on initial feedback, and (5) clear communication and leadership.It has been shown that a surgical oncology cold hub with an accessible referral system and an effective system of preoperative screening system can minimize COVID-19 transmission, morbidity, and mortality, in a region with heavy disease prevalence. This structure represents a safe, ethical, and viable system that can be replicated in other health care systems.

BACKGROUND:Understanding the optimal management of distal biceps femoris avulsion injuries is critical for restoring preinjury function, restoring hamstring muscle strength, increasing range of motion, and minimizing risk of complications and recurrence. Due to the rarity of these injuries, prognosis and outcomes within the literature are limited to case reports and small case series. PURPOSE:To assess the effect of surgical repair for acute distal avulsion injuries of the biceps femoris tendon on (1) return to preinjury level of sporting function and (2) time to return to preinjury level of sporting function, patient satisfaction, and complications. STUDY DESIGN:Case series; Level of evidence, 4. METHODS:This prospective single-surgeon study included 22 elite athletes (18 men [82%], 4 women [18%]; mean age, 26 years; age range, 17-35 years; mean body mass index, 25.3 ± 4.1 kg/m2) undergoing primary suture anchor repair of avulsion injuries of the distal biceps femoris confirmed on preoperative magnetic resonance imaging. Predefined outcomes relating to time for return to sporting activity, patient satisfaction, complications, and injury recurrence were recorded at regular intervals after surgery. Minimum follow-up time was 12 months (range, 12.0-26.0 months) from the date of surgery. RESULTS:The mean time from injury to surgical intervention was 12 days (range, 2-28 days). All study patients returned to their preinjury level of sporting activity, predominately professional soccer or rugby. Mean time from surgical intervention to return to full sporting activity was 16.7 ± 8.7 weeks. At 1- and 2-year follow-up, all study patients were still participating at their preinjury level of sporting activity. There was no incidence of primary injury recurrence, and no patients required further operation to the biceps origin. CONCLUSION:Surgical repair of acute avulsion injuries of the distal biceps femoris facilitated early return to preinjury level of function with low risk of recurrence, low complication rate, and high patient satisfaction in elite athletes. Suture anchor repair of these injuries should be considered a reliable treatment option in athletes with high functional demands to permit an early return to sport with restoration of hamstring strength.

A new fluted, titanium, monobloc stem with a three degree taper has been designed in an attempt to overcome the challenges associated with femoral reconstruction in the setting of extensive bone loss. The aim of this study was to report its early clinical and radiographic outcomes. This is a retrospective review of prospectively collected data carried out at a single institution between Jan 2017 and Dec 2019. Forty-three femoral revisions were performed using a new tapered, fluted, titanium, monobloc (TFTM) revision stem. Complications, clinical and radiographic data were obtained from medical records and a locally maintained database. Clinical outcomes were assessed using the Oxford Hip Score (OHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). All post-operative radiographs were analysed for subsidence, osteolysis and femoral cortical bone remodelling. Mean follow-up was 24 months (range 8–42 months). Subsidence of 1.2 mm was noted in one patient. No cases of clinically significant subsidence (> 10 mm) were observed. At final follow-up, a statistically significant improvement was noted in functional outcome scores. The mean OHS preoperatively and at final follow-up were 24 (SD 13) and 42 (SD15). p = 0.04 mean difference 18 (95% CI 15–22). The mean WOMAC scores preoperatively and at final follow-up were 62 (SD23) and 88 (SD7) respectively (p < 0.001, mean difference 26; 95% CI 21–34). No stem fractures were noted within the follow-up period. Positive early clinical and radiological outcomes have been observed with this tapered, fluted, titanium, monobloc stem. Based on these results, this implant may be considered as a viable option in the majority of uncemented femoral revisions.

Background: Surgical repair of proximal hamstring avulsion injuries can enable the return to preinjury levels of sporting function and minimize the risk of recurrence in both professional and recreational athletes. While venous thromboembolism (VTE) is a recognized complication of surgical repair, the incidence thereof is poorly reported in the literature. Purpose/Hypothesis: To report the incidence of symptomatic VTE after proximal hamstring avulsion repair and assess the efficacy of our thromboprophylaxis protocol. It was hypothesized that the incidence of VTE after proximal hamstring avulsion repair is low and that aspirin is an adequate choice of chemical prophylaxis. Study Design: Cohort study; Level of evidence, 2. Methods: We performed a prospective cohort study of 2 groups of patients who underwent proximal hamstring avulsion (partial and complete) repair between 2000 to 2020 with different thromboprophylaxis protocols. No patients were routinely screened for VTEs, and VTE was investigated only if clinically indicated. Prospectively collected data included demographics, the mechanism and sport that caused injury, use of bracing, and clinical diagnosis of deep vein thrombosis (DVT) or pulmonary embolism (PE). The first cohort (n = 380) was given mechanical prophylaxis in the form of compression stockings for 6 weeks postoperatively. The second cohort (n = 600) was given compression stockings and aspirin 150 mg once daily routinely, or prophylactic low–molecular weight heparin in high-risk individuals, until the 6-week follow-up. Patients in both cohorts underwent early mobilization after surgery; a hinged knee brace locked at 60° to 120° was provided if the tendon repair was under significant tension. The surgical technique and rehabilitation protocol remained consistent throughout the study. Results: The overall incidence of symptomatic VTE was 0.51%. A total of 5 patients developed symptomatic VTEs (3 DVTs, 2 PEs) in the first cohort, and no patients developed symptomatic VTEs in the second cohort (1.32% vs 0%; P = .0048). Conclusion: The incidence of symptomatic VTE after proximal hamstring avulsion repairs was extremely low. A combination of aspirin, early mobilization despite bracing, compression stockings, and good hydration was an effective thromboprophylaxis strategy.

BACKGROUND:We describe the intraoperative parameters that affect stem subsidence rates in tapered modular femoral stems for revision total hip arthroplasty (THA). We also determine the effect of the stem bicortical contact on subsidence rates and whether there is a minimum threshold bicortical contact that must be achieved to avoid the complication of subsidence. METHODS:This is a retrospective cohort study consisting of 109 hips in 105 patients (53 males and 52 females) at a minimum of 2 years of follow-up. All revisions were carried out for Paprosky type 3A and 3B femoral deficits. Clinical outcomes included the indication for revision, aseptic re-revision surgery, specifications of the stem inserted, and specifications of the femoral head and acetabular components implanted. Radiographic outcome measures included subsidence (mm) and bicortical contact (mm). RESULTS:Using multivariate regression analysis, 3 parameters were associated with an increased rate of stem subsidence. A reduced bicortical contact distance (P < .001) and a stem length of ≤155 mm (P < .001) were both associated with higher subsidence rates. We also demonstrated a novel threshold of 20-mm bicortical contact which must be achieved to significantly reduce subsidence rates in these modular femoral stems for revision THA. CONCLUSION:Subsidence rates of modular tapered femoral stems for revision THA can be significantly reduced by increasing the initial bicortical contact of the stem within the diaphysis and the overall length of the femoral stem >155 mm. We describe a minimum threshold bicortical contact distance of 20 mm that should ideally be exceeded to significantly reduce the risk of stem subsidence within the femoral canal.

Revision hip arthroplasty presents a challenge in the setting of femoral bone loss. Tapered stems are susceptible to subsidence which leads to leg length inequality, hip instability and may necessi...

Background: As imaging technology improves small Pulmonary Emboli (PE) of debatable clinical relevance are increasingly detected leading to higher numbers of patients receiving anticoagulation. Although PE are an important cause of morbidity and mortality in patients undergoing repair of proximal femur fractures, this cohort of patients are at increased falls risk and are therefore largely unsuitable for long term anticoagulant therapy. Objective: 1. To review sequential Computed Tomography Pulmonary Angiograms (CTPA) performed in patients who underwent repair of proximal femur fractures at our institution. 2. To establish the perioperative CT imaging performed. Design: A retrospective cross sectional study of all patients undergoing proximal femur fracture repair at a single tertiary referral. Methods: The theatre database was interrogated to reveal all patients undergoing proximal femur fracture repair over a 28 month period from 01/01/12 to 07/04/14 inclusive. This was cross-referenced with the Picture Archiving Communication System (PACS) to establish all imaging undertaken in the perioperative period. CTPA studies performed within the time period of 1 week prior to and 6 months post proximal femur fixation were included. CTPA studies and reports were assessed for quality and findings. D-Dimer results, if performed within 72 hours of the CTPA study, were recorded. Results: 1388 patients underwent neck of femur fracture repair in the 28-month study period. Of this cohort 71 CTPA studies were performed in 71 patients (5.2%) with a mean age of 77.8 years (range 38 - 100). 53 (74.6%) of studies were negative for embolus and 17 (23.9%) studies revealed clot in a pulmonary artery (1 saddle embolus, 2 main pulmonary artery emboli, 7 lobar vessel emboli, 2 segmental artery emboli, 5 subsegmental emboli). Overall PE detection rate was 1.2% of our total study population. In all 71 studies, Houndsfield Unit (HU) in the main pulmonary artery (PA) was >200; which is considered to be of satisfactory quality to assess for segmental pulmonary emboli. 32% of patients had D Dimer levels performed, however no relationship with presence of PE on CTPA was demonstrated. Conclusion: The rate of positive CTPA studies in patients undergoing proximal femur fracture repair is 23.9% in our patient population, comparing favorably to published data. This is likely to reflect good compliance with prevention measures at ward level. D-Dimer results are unreliable for PE prediction.

Spinal haematoma is a rare occurrence, however has the potential to cause significant spinal injury and morbidity. MRI is the gold-standard of investigation, and urgent imaging is required for early diagnosis and treatment to ensure best patient outcomes. We present a pictorial review demonstrating the imaging features of spinal haematoma based on meningeal space assignment; epidural, subdural, subarachnoid, intramedullary and a combination of these locations. In this review, we summarise the literature and imaging findings of spinal haematoma on MRI. Particular imaging features which help to differentiate between haematoma in the different spinal meningeal compartments are discussed below.