Muller-Weiss disease is an uncommon condition with unclear etiology and no gold standard treatment. The question arises; which joints to fuse? Although no consensuses prevail, one must postulate fusion should include those affected. Consequently, to establish an algorithm for its surgical management we set out to study clinical and radiographic features with use of SPECT-CT and a literature review. 57 consecutive feet presenting with Muller-Weiss disease analysed; 15 men, 25 women, age 22–84. Condition bilateral in 17, left side 16, right in 7 patients. Specific history and examination by senior author. Radiographic series and SPECT-CT obtained with surgery performed on significantly symptomatic feet. Measurements of Meary-Tomeno angles, anteroposterior thickness of navicular at the midpoint of each naviculo-cuneiform, alongside the medial extrusion distance and percentage of compression in each case performed. Poor correlation between Meary's angle and 1) degree of compression at naviculo-cuneiform joints, 2) degree of extrusion 3) compression vs extrusion using R2 coefficient of determination (invalidating Maceira et al. classification). In unilateral cases, extrusion significantly greater on affected side 94.7% (P< 0.001 Fisher exact test). Degree of extrusion significantly greater in bilateral than unilateral cases (p=0.004 unpaired T test). Valgus hindfoot and Meary's negative most common pattern with no correlation between heel alignment and Meary's R2 = 0.003. SPECT-CT useful to determine subtalar involvement in ‘stage 2 disease.’ Following review of cases and published literature we propose the following classification for Muller-Weiss disease with treatment algorithm. 3 Stage delineation; Stage 1 (Normal hindfoot alignment); 1A. Talonavicular disease only - Isolated Talonavicular arthrodesis 1B. Talonavicular + Subtalar; double medial or triple arthrodesis. Stage 2. Talonavicular + Naviculocuneiform; 2A. Adequate bone stock - Talo-naviculo-cuneiform arthrodesis, 2B. Inadequate bone stock +- subtalar disease; Talo-naviculo-cuneiform arthrodesis with tricortical bone graft (Mayich). Stage 3; Asymmetric ankle varus. Pantalar arthrodesis Double/triple/TNC/TAR arthrodesis with hindfoot re-alignment.
Ankle fractures in the elderly are an increasing problem with our aging population. Options for treatment include non-operative and operative with a range of techniques available. Failure of treatment can lead to significant complications, morbidity and poor function. We compared the outcomes of two operative techniques, intramedullary hindfoot nailing (IMN) and fibular-pro-tibia fixation (FPT). This is the largest analysis of these techniques and there are no comparative studies published. We retrospectively reviewed patients over the age of 60 with ankle fractures who were treated operatively between 2012 and 2017. We identified 1417 cases, including 27 patients treated with IMN and 41 treated with FPT. Age, sex, co-morbidities and injury pattern were collected. Primary outcome was re-operation rate. Secondary outcomes included other complications, length of stay and functional status.Introduction
Method
Total ankle replacement as a valid treatment for end stage ankle arthritis, is gaining popularity and every year there is an increasing number of procedures. With revision rates as high as 21% at 5 years and 43% at 10 years there is a need for understanding and reporting the outcome of revision ankle replacement. Our aim was to study the patient reported outcomes following revision TAR with a minimum of 2 year follow up. All patients that underwent a revision total ankle replacement between 2012 and 2016 were included in the study. All patients received a post-operative questionnaire comprising of MOX-FQ score, EQ-5D (UK) and Foot and Ankle outcomes scores (FAOS) and patients satisfaction questionnaire with a minimum of 2 years follow up.Introduction
Methods
Total ankle replacements (TARs) are becoming increasingly more common in the treatment of end stage ankle arthritis. As a consequence, more patients are presenting with the complex situation of the failing TAR. The aim of this study was to present our case series of isolated ankle fusions post failed TAR using a spinal cage construct and anterior plating technique. A retrospective review of prospectively collected data was performed for 6 patients that had isolated ankle fusions performed for failed TAR. These were performed by a single surgeon (IW) between March 2012 and October 2014. The procedure was performed using a Spinal Cage construct and grafting in the joint defect and anterior plating. Our primary outcome measure was clinical and radiographic union at 1 year. Union was defined as clinical union and no evidence of radiographic hardware loosening or persistent joint lucent line at 1 year.Background
Methods
AlloStem/Cellular Bone Allograft and autologous bone graft are accepted methods for managing hindfoot degenerative arthritis. The purpose was to evaluate outcomes of AlloStem and autograft in subtalar arthrodesis and compare overall fusion rates. This study was conducted in IRB compliance. Patients between 18–80 years who qualified for a subtalar fusion were randomized 1:1 to AlloStem or autologous graft. The AOFAS hindfoot ankle scale, FFI-R and SF-12 were collected pre-operatively, 6 weeks, 3 & 6 months, 1 and 2 year. Weight-bearing 3-view ankle X-rays were done at the same intervals. A CT scan was obtained at 6 months.Introduction
Methods
Lateral ankle instability is a common problem, but the precise role of the lateral ankle structures has not been accurately investigated. This study aimed to accurately investigate lateral ankle complex stability for the first time using a novel robotic testing platform. A six degrees of freedom robot manipulator and a universal force/torque sensor were used to test 10 foot and ankle specimens. The system automatically defined the path of unloaded plantar/dorsi flexion. At four flexion angles: 20° dorsiflexion, neutral flexion, 20° and 40° of plantarflexion; anterior-posterior (90N), internal-external (5Nm) and inversion-eversion (8Nm) laxity were tested. The motion of the intact ankle was recorded first and then replayed following transection of the lateral retinaculum, Anterior Talofibular Ligament (ATFL) and Calcaneofibular Ligament (CFL). The decrease in force/torque reflected the contribution of the structure to restraining laxity. Data were analysed using repeated measures of variance and paired t-tests.Background
Method
Large osteochondral defects (OCD) of the talus present a difficult management conundrum. We present a series of Maioregen xenograft patches applied through an open approach, early lessons from the technique and good early outcomes, in patients who are otherwise looking at ankle salvage techniques. 16 patients underwent open patch procedures, performed by a single surgeon, over a 30 month period. 12 males, and 4 females with age at presentation from 21–48. The majority were young, male, in physical employment with active sporting interest. MoxFQ, and E5QD were collected preop, 3, 6, 12 month postoperatively. There were significant improvements in ROM, pain, and scores in the cohort. 3 cases returned to Theatre, 1 for a concern about late infection, which settled with good outcome, and a further 2 with metalwork / adhesions.Introduction
Results
Surgical options for management of a failed ankle arthroplasty are currently limited; typically conversion to fusion is recommended with only a few patients being considered for revision replacement surgery. This paper presents our experience of revision ankle replacements in a cohort of patients with failed primary replacements. A total of 18 revision TAR in 17 patients were performed in patients with aseptic loosening. The technique was performed by a single surgeon (CSK) over a 4 year period between July 2014 and August 2018 using the Inbone total ankle replacement system. Patient demographics and clinical outcomes were collected retrospectively using - MOXFQ, EQ5D, VAS pain score and patient satisfaction questionnaires.Aim
Method
Venous Thrombo-Embolism is a recognized complication of lower limb immobilization. In the neuropathic patient total contact casting (TCC) is used in the management of acute charcot neuroathropathy and/or to off-load neuropathic ulcers, frequently for long time periods. To our knowledge there is no literature stating the prevalence of VTE in patients undergoing TCC. We perceive that neuropathic patients with active charcot have other risk factors for VTE which would predispose them to this condition and would mandate the use of prophylaxis. We report a retrospective case series assessing the prevalence of VTE in the patients being treated with TCCs. Patients undergoing TCC between 2006 and 2018 were identified using plaster room records. These patients subsequently had clinical letters and radiological reports assessed for details around the TCC episode, past medical history and any VTE events.Background
Methods
The aim of this study was to determine the fracture haematoma (fxH) proteome after multiple trauma using label-free proteomics, comparing two different fracture treatment strategies. A porcine multiple trauma model was used in which two fracture treatment strategies were compared: early total care (ETC) and damage control orthopaedics (DCO). fxH was harvested and analyzed using liquid chromatography-tandem mass spectrometry. Per group, discriminating proteins were identified and protein interaction analyses were performed to further elucidate key biomolecular pathways in the early fracture healing phase.Aims
Methods
Hip arthroscopy (HA) is an effective treatment for various hip conditions but has a steep learning curve and its effect on long-term joint preservation is unclear. This study uses population-level data to assess (1) the 90-day complication rate, and (2) the frequency and timing of revision HA, total hip replacement (THR), and pelvic osteotomy (PO) following primary HA. We performed a retrospective analysis of the National Hospital Episode Statistics database, examining all patients who underwent primary HA in NHS hospitals in England from 2010 to 2023 using relevant OPCS-4 codes. We evaluated patient demographics, 90-day complications, and reoperation rates for revision HA, THR, and PO. Descriptive statistical analyses were performed to calculate frequencies and average time to reoperations. We included 22,401 HA procedures in the study. The mean LOS was 0.82±2.04 days. The 90-day readmission rate was 0.17% at a mean of 54.4±8.1 days. The most common reasons for readmission were reoperation (0.071%), followed by infection (0.031%), pulmonary embolism (0.027%), pain (0.022%), bleeding (0.018%), and deep vein thrombosis (0.004%). One patient died within 90 days. Overall, 4942 patients (22.1%) required further surgery at a mean of 2.71±2.27 years. The rates of revision HA, conversion to THR, and PO were 6.94%, 14.6%, and 0.50% at a mean of 2.39±1.79, 2.87±2.46, and 2.26±1.80 years respectively. Female patients had higher rates of reoperation than males for conversion to THR (9.99% vs 4.63%), revision HA (4.92% vs 2.02%), and subsequent PO (0.43% vs. 0.06%) (p<0.001). This study demonstrates a low short-term complication rate after primary HA, supporting existing literature. However, a large proportion of patients required further surgery, especially females. These findings highlight the need for careful patient selection and counselling before HA to optimise outcomes, as well as further research on factors influencing longer-term outcomes and cost-effectiveness.
Total Hip Arthroplasty (THA) and Hip Hemiarthroplasties (HA) are successful, cost-effective procedures that improve quality of life. Dislocation is a well recognised complication with a significant health and economic burden. We aim to establish the current management practices across the United Kingdom (UK) for Prosthetic Hip Dislocations (PHD). Our definition of a PHD includes; THA, HA and revision THA. This national study builds on our regional pilot study and records one of the largest datasets of Prosthetic Hip Dislocation management within the UK. A trainee-led collaborative; the North West Orthopaedic Research Collaborative (NWORC). Conducted a retrospective audit, registered as Quality Improvement (QI) projects, collected data from 38 hospital trusts across the UK. Data was collected on patient-related factors, inpatient management, and outpatient follow up of each PHD episode between January and July 2019. Primary outcome measured definitive management, in the form of revision surgery or the consideration for this through a referral pathway. A total of 673 (THA 504, Revision THA 141, HA 28) patients were included with a total of 740 dislocation episodes. Mean age was 75.6 years with female to male ratio 2:1. The majority of PHDs were a result of a low energy mechanism (98.7%) and presented over 6 months post index procedure (80.5%). Over half (53.8%) attended with a first or second time dislocation. Only 29.9% patients received onward revision referral; whereas 70.1% followed diverse management patterns, including local non-arthroplasty and primary arthroplasty surgeon follow-ups. Revision THAs had higher rates of referral for revision (p<0.001) compared to primary THA and HA dislocations. A high number of PHDs present across the UK, with under a third receiving definitive management plans. This variation increases the economical burden to the National Health Service, highlighting the need for national guidance to manage these complex patients.
Ceramic bearing fracture is a rare complication following implantation using modern day ceramic bearing materials. Revision bearing options in such cases is debated, with the choice between ceramic-on-ceramic and ceramic-on-polyethylene bearings. Revision to a hard on soft bearing raises concerns about potential catastrophic wear secondary to a third-body reaction caused by the fractured ceramic particles. Data was collected retrospectively from the NJR, electronic patient records, revision database and picture archiving and communication system. Templating software was used to determine linear wear between first post-operative radiograph and the latest available follow up. Univariate analysis was used to examine patient demographics and the wear rates for revision of ceramic bearing fractures to ceramic on polyethylene components. The intra and inter-rater reliability of wear measurements was calculated. There were twelve patients identified as meeting the inclusion criteria. The average age at revision was 62 years (54–72). There were 6 liner and 6 head fractures revised to delta ceramic heads and cross-linked polyethylene acetabular components. The most frequently used head size was 32mm. At mean follow up of 3.8 years (0.5 6.1 years), median 4.4 years, linear wear rate was calculated at 0.08± 0.06 mm/year. Both intra-rater and inter-rater reliability was excellent with ICC scores of 0.99 at all timepoints. Revision to ceramic on polyethylene (CoP) bearings following ceramic fracture does not cause early catastrophic wear at early follow up. It appears safe to use this hard on soft bearing combination, given that wear rates are comparable to what is expected in a primary hip replacement setting. Longer follow up is required to establish if this trend persists.
Radiological investigations are essential in the work-up of patients presenting with non-arthritic hip pain, to allow close review of the complex anatomy around the hip and proximal femur. The aim of this study is to quantify the radiation exposure associated with common radiological investigations performed in assessing young adult patients presenting with non-arthritic hip pain. A retrospective review of our UK tertiary hip preservation centre institutional imaging database was performed. Data was obtained for antero-posterior, cross-table lateral and frog-lateral radiographs, along with data for the low dose CT hip protocol and the Mako CT Hip protocol. The radiation dose of each imaging technique was measured in terms of dose-area product (DAP) with units of mGycm2, and the effective doses (ED, mSv) calculated. The mean effective radiation dose for hip radiographs was in the range 0.03 to 0.83mSv (mean DLP 126.7–156.2 mGycm2). The mean effective dose associated with the low-dose CT hip protocol was 3.04mSv (416.8 mGycm2) and for the Stryker Mako CT Hip protocol was 8.4mSv (1061 mGycm2). The radiation dose associated with use of CT imaging was significantly greater than plain radiographs (p<0.005) Investigation of non-arthritic hip pain can lead to significant ionising radiation exposure for patients. In our institution, the routine protocol is to obtain an anteroposterior radiograph and then a specific hip sequence 3 Tesla MRI including anteversion views. This provides the necessary information in the majority of cases, with CT scanning reserved for more complex cases where we feel there is a specific indication. We would encourage the hip preservation community to carefully consider and review the use of ionising radiation investigations.
Periprosthetic joint infection is a serious complication of primary total hip replacement (THR) with significant associated morbidity. In acute infection, Debridement, Antibiotics and Implant Retention (DAIR) may be considered. Current national guidelines recommend a DAIR should be performed by “an experienced arthroplasty surgeon┕ but do not specify the need for this to be a revision arthroplasty surgeon. We investigated outcomes in our NHS Trust of DAIR procedures performed by revision and non-revision arthroplasty surgeons. Infection registry data and patient records were analysed for all DAIR procedures of infected primary THRs between 2017 and 2021. Data collected included details of the primary surgery, the presentation with infection, the DAIR procedure and any subsequent complications including return to theatre at any time point. Routinely collected pre- and post-operative patient reported outcome measures (PROMs) were reviewed. 54 periprosthetic joint infections of primary THRs received a DAIR procedure. 41 DAIRs were performed by a revision surgeon and 13 by non-revision surgeons. There was no significant difference in time from primary THR to presentation with infection, time from presentation to DAIR or pre-operative C-reactive protein between the two groups. In 21 (38.9%) patients the DAIR procedure was classed as a treatment failure; 17 patients (31.5%) returned to theatre for further revision surgery, one (2.4%) died related to infection and three (5.6%) had persistent infection but did not receive further surgery. Treatment failure was significantly higher in the non-revision surgeon group (9/13 (69.2%)) than in the revision surgeon group (12/41 (29.3%)) (p = 0.02). Overall, improvement in PROMs after DAIR was seen at both six and 12 months. The overall success rate of DAIR was 61.1% and there was a sustained improvement in PROMs after surgery. However, there was a significant difference in failure rates between revision surgeons and non-revision surgeons.
The aims were to assess whether preoperative joint-specific function (JSF) and health-related quality of life (HRQoL) were associated with level of clinical frailty in patients waiting for a primary total hip arthroplasty (THA) or knee arthroplasty (KA). Patients waiting for a THA (n=100) or KA (n=100) for more than six months were prospectively recruited from the study centre. Overall, 162 patients responded to the questionnaire (81 THA; 81 KA). Patient demographics, Oxford score, EuroQol five dimension (EQ-5D) score, EuroQol visual analogue score (EQ-VAS), Rockwood Clinical Frailty Score (CFS), and time spent on the waiting list were collected. There was a significant correlation between CFS and the Oxford score (THA r=ˆ’0.838; p<0.001, KA r=ˆ’0.867; p<0.001), EQ-5D index (THA r=ˆ’0.663, p<0.001; KA r=ˆ’0.681; p< 0.001), and EQ-VAS (THA r=ˆ’0.414; p<0.001, KA r=ˆ’0.386; p<0.001). Confounding variables (demographics and waiting time) where adjusted for using multiple regression analysis. For each 8.5 (THA, 95% CI 7.1 to 10.0; p<0.001) and 9.9 (KA, 95% CI 8.4 to 11.4; p<0.001) point change in the Oxford score, there was an associated change in level of the CFS. For each 0.16 (THA, 95% CI 0.10 to 0.22; p<0.001) and 0.20 (KA, 95% CI 0.12 to 0.27; p<0.001) utility change in EQ-5D, there was an associated change in level of the CFS. EQ-VAS (THA, B=ˆ’11.5; p<0.001, KA B=ˆ’7.9; p=0.005) was also associated with CFS. JSF and HRQoL in patients awaiting THA or KA for more than six months, were independently associated with level of clinical frailty. With further prospective studies, clinical frailty may prove to be a useful metric to assist in the prioritization of arthroplasty waiting lists.
Preoperative anaemia and intraoperative blood loss result in ∼90% of individuals being anaemic following hip and knee arthroplasty. Reducing blood loss offers the opportunity to improve outcomes and reduce the risk of transfusion and costs. This review's aim was to determine the effectiveness of drugs for preventing blood loss, and identify optimal dose, route, and timing of administration. Cochrane network meta-analysis of randomised controlled trials was conducted. Inclusion criteria: adults undergoing primary or revision elective hip or knee arthroplasty. Drugs studied: tranexamic acid (TXA), aprotinin, epsilon-aminocaproic acid, desmopressin, factor VIIa and XIII, fibrinogen, fibrin sealants, and non-fibrin sealants. Primary outcomes: need for allogenic blood transfusion, all• cause mortality (within 30 days). Secondary outcomes: mean number of transfusion episodes, re-operation, length of hospital stay and adverse events (DVT, PE, CVA, MI). 102 studies with 8418 participants. Trials included more women (63%). 47 studies (4398 participants) were included within the blood transfusion NMA. TXA given intra-articularly and orally at a total dose of greater than 3g pre-incision, intraoperatively and postoperatively ranked the highest, with anticipated absolute effect of 147 fewer transfusions per 1000 (53% chance ranking 1st) (relative risk(RR) 0.02, 95% credible interval(CrI) 0–0.31); moderate-certainty). Aprotinin (RR 0.59, 95%:CrI 0.36–0.86; low certainty evidence), fibrin (RR 0.86, CrI 0.25–2.93; very-low certainty) and EACA (RR 0.60, 95%:CrI 0.29–1.27; very-low certainty) were not shown to be as effective as TXA. TXA was the most effective drug for preventing bleeding in lower limb arthroplasty. Aprotinin and EACA were not as effective. Currently, the optimal dose, route and timing of administration of TXA is unclear. However, TXA given at higher doses and via mixed routes ranked higher in the treatment hierarchy. Oral TXA may be as effective as intavenous. There was no evidence of harm associated with higher doses of TXA.
Polymethylmethacrylate (PMMA) bone cement is strong in compression, however it tends to fail under torsion. Sufficient pressurisation and subsequent interdigitation between cement and bone are critical for the mechanical interlock of cemented orthopaedic implants, and an irregular surface on the acetabular cup is necessary for reasonable fixation at the cup-cement interface. There is limited literature investigating discrepancies in the failure mechanisms of cemented all-polyethylene acetabular cups with and without cement spacers, under torsional loading. In vitro experimental comparison of three groups of polyethylene acetabular prosthesis (PAP) cemented into prepared sawbone hemipelvises: * PAP without PMMA spacers maintaining an equal cement mantle circumferentially. (Group 1 n=3) * PAP without PMMA spacers cemented deliberately ‘bottoming-out’ the implant within the acetabulum. (Group 2 n=3) * PAP with PMMA spacers. (Group 3 n=3) The constructs were tested to torstional failure on a custom designed setup, and statistical analysis done by a one-way ANOVA and Tukey-Welsh test. Group 3 demonstrated superior torsional resistance with a statistically significant torque of 145Nm (SD±12Nm) at failure, compared to group 2 (109Nm, SD±7Nm) and group 1 (99Nm, SD±8Nm). Group 3 experienced failure predominantly at the bone-cement interface, in contrast, Groups 1 and 2 exhibited failure predominantly at the cup-cement interface. There was no significant difference between Group 1 and 2. Qualitative analysis of the failure mode indicates the efficient redistribution of stress throughout the cement mantle, consistent with the greater uniformity of cement. PMMA spacers increase the resistance to torsional failure at the implant-cement interface. Acetabular components without spacers (Groups 1 and 2) failed at the implant-cement interface before the cement-bone interface, at a statistically significantly lower level of torque to failure. Although the PMMA spacers may reduce cement interdigitation at the cement-bone interface the torsional forces required to fail are likely supraphysiological.
The postoperative pain after hip arthroscopy remains a major challenge in the immediate postoperative period. Adequate postoperative analgesia has been associated with increased patient satisfaction and decreased consumption of opioids. We evaluated the efficacy of pericapsular nerve group block (PENG) versus fascia iliaca block (FIB) in reducing post-operative pain and analgesic consumption within the first 24 hours following arthroscopic management of femoroacetabular impingement (FAI). Thirty-nine patients (17 females and 25 males, ages 18–42 years, mean ± SD (27.9 ± 6.2), and mean BMI of 25.13±5.08 kg/m2 were scheduled for primary arthroscopic management of FAI. Included patients were randomized into two groups according to the block used in each. Group (A) 19 patients were included and had FIB and group (B) 20 patients were included and received PENG block. The efficacy of both techniques was clinically and statistically valuated using VAS score and quadriceps muscle power. There was a statically significance difference in the mean at rest between the two groups at all measured time points following surgery (6, 12, 18 and 24 h). Also, in dynamic pain scores (with hip flexion) scores were statistically significant at 24 hours post-operative (P = .001). Total opioid consumption in the first 24 hours postoperative was lower in the PENG group with significant difference of mean 16.5 ±9.9 mg for PENG group versus 27.5±9.6 mg for FIB group (P < .005). Five patients (26.31%) in FIB group had weaker quadriceps muscle power while none in PENG group patients had quadriceps weakness. PENG block might be considered as an ideal regional anesthesia modality for hip arthroscopy. As an alternative to more conventional regional nerve blocks such as a fascia iliaca block. PENG block is easily performed in the preoperative setting, and appears to spare motor function while providing a prolonged sensory pain relief.
There is an increasing demand worldwide for total hip arthroplasty in patients over 80 years old. This study is the largest of its kind reporting long term outcomes and clinical survivorship of patients over 80 years old undergoing THR. 13171 patients 80 years or older who underwent THR between 2000 and 2019 were included. Demographic and operative data was collected including age, sex, laterality, date of surgery and operative technique. Presence and date of complications were collected. Data was also collected for the same time period on 80910 patients aged 51–79 years undergoing THR for comparison. 4103 (31.2%) male and 9068 female (68.8%) patients were included in the 80year old cohort. Median age was 83 (IQR 81–83, range 80–98). 32682 (40.4%) male and 48227 (59.6%) females were included in the 50–79year old cohort. Median age was 68 (IQR 62–73, range 50–79). The 80 cohort was more likely to sustain post operative complications in the 6 months following surgery including DVT (81/13171 vs 364/80910, P<0.05), myocardial infarction (177/13171 vs 341/80910, P<0.05), acute renal failure (371/12800 vs 812/80910 P<0.05). The 50–79year old cohort was over twice as likely to undergo revision surgery than the 80 year old cohort (HR 2.55, 95% CI 2.216–2.932, p<0.001). Of those requiring revision surgery, the elderly cohort were more likely to undergo earlier revision surgery (378days, 95%CI 236–519d vs 1586days, 95%CI 1471–1700d, p<0.001). In those undergoing revision surgery, a higher proportion were done for infection in the 80 year old cohort (39/219 (17.8%) vs 215/2809 (7.7%), p<0.05. This study demonstrates good outcomes in terms of medical complications and a low overall risk of requiring revision surgery in patients 80years old undergoing THR. Patients over the age of 80 should be counselled on the relatively increased risk of medical complications post operatively.
