The Montgomery ruling advocates patients be informed of ‘material risks’ of a procedure. With no guidelines for patients wishing to return to high activity levels after knee arthroplasty, we explore patient and surgeon perceptions in climbers. Ethical approval was granted by the University of Central Lancashire. Anonymous questionnaires were sent via email and social media to consultant knee arthroplasty surgeons and to climbers/mountaineers across the UK. Consultants were asked about advice given for patients who participate in climbing. Climbers were asked about their experiences of knee arthroplasty and return to activity. Of 33 knee arthroplasty surgeons, 11(33%) were firmly against any return to climbing, 10(30%) counselled against it, and 12(36%) were open to return to previous activity. Of 11(33%) surgeons who do not gather information about levels of climbing, 8 would not provide specific advice regarding risks of returning to sport. Of 28 climbers, only 5(18%) were informed to cease completely, with 11(39%) cautioned against and 12(43%) permitted to return. There was no correlation between the advice received and climbing ability post-operatively, (kappa=0.143,p=0.058), with a substantial agreement between ability 1-year post-operatively and currently, (kappa=0.689,p<0.001). There is a discrepancy between the advice given and received by climbers/mountaineers prior to knee arthroplasty, with ability post-operatively having no relationship to advice given. Climbing is possible at high level with no reported complications following knee arthroplasty. The 1-year time point is predictive of longer-term outcome. This information should help surgeons better inform their patients preoperatively.Abstract
Climbers and mountaineers will present to arthroplasty surgeons in need of hip replacement surgeries. There is a lack of guidance for both parties with a paucity in the literature. Climbing is often considered a high-risk activity to perform with a total hip replacement, due to the positions the hip is weighted in, and the potential austere environment in which an injury may occur. The aim was to assess levels of climbing and mountaineering possible following hip arthroplasty, and any factors affecting these levels. Ethical approval was obtained from the University of Central Lancashire. An anonymous online questionnaire was disseminated via email, social media and word-of-mouth to include all climbers, hill-walkers or mountaineers across the UK. This was used to collect climbing and mountaineering ability at various timepoints, along with scores such as the Oxford Hip Score and UCLA Score. The Kappa statistic was used to assess for correlations. Of the responders, 28 had undergone right hip arthroplasty surgery, with 11 having left hips and 22 receiving bilateral hips. A total of 67 of the replaced hips were total hip replacements, with 16 having undergone hip resurfacing. There is a fair agreement in level of climbing ability 3 months pre- and 3 months post-operatively (kappa=0.287, p<0.001), and a substantial agreement between 1 year post-operatively and currently for both climbing (kappa=0.730, p<0.001) and mountaineering (kappa=0.684, p<0.001). Impressively, 17 participants are climbing at more than E1 trad or 6c sport at one or more time points post operatively, which is regarded as an advanced level within the climbing community. Out of those 17 participants, 8 were climbing at this level within 3 months post-operatively. The level of climbing possible following hip arthroplasty surgery is above what is expected and perhaps desired by the operating surgeon. It is essential to take the individual patient into account when planning an operative intervention such as arthroplasty. The one year post-operative time point is highly predictive of longer term outcomes for both climbing and mountaineering.
Orthopaedic surgeons frequently use opioids for peri-operative pain management and there is considerable variability in the amount prescribed between surgeons. As such, the appropriate number of opioids to prescribe for specific procedures is often unknown. Leftover prescription opioids are at risk for diversion to family and friends for nonmedical use. The aim of this study was to determine the optimal amount of narcotics to prescribe postoperatively for patients undergoing hip arthroscopy. 23 consecutive patients were enrolled. All patients were prescribed 60 tablets of hydrocodone/acetaminophen 10/325 postoperatively as part of a multimodal pain management strategy. Patients were called at 14 and 21 days post-operatively to tabulate the number of pills used and knowledge of how to properly dispose of pills. The median number of narcotic pain pills required was 6 (IQR: 3,15). Over half of patients (56.5%) required ≤10 narcotic pain pills postoperatively. A large number of narcotic tablets (1071/1380, 77.6%) were unused and a small percentage of patients (8/23, 34.8%) were aware of proper disposal techniques. Knowledge of how to properly dispose of unused narcotics was protective against a prolonged duration of narcotic use postoperatively (Parameter estimate −5.7, 95% CI: −11.3, −0.1, p = 0.045). Reducing the number of prescribed narcotic tablets to 25 would meet the post-operative pain demands of over 85% of hip arthroscopy patients. More judicious post-operative prescribing patterns and patient education regarding disposal may help minimize physician contribution to opioid misuse, overuse and diversion.
Recent studies have described safe outcomes for short-stays in the hospital after total shoulder arthroplasty. The purpose of this study is to identify pre-operative and operative risk factors for hospital admissions exceeding 24 hours. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried from 2006 to 2016 for the current procedural terminology (CPT) billing code related to total shoulder arthroplasty. Patients were then grouped as either having a length of stay (LOS) equal to or less than 24 hours or greater than 24 hours. Patients admitted to the hospital prior to the day of surgery were excluded. Patient demographics, co-morbidities, and operative time were then analyzed as risk factors for a hospital stay exceeding 24 hours. Pre-operative co-morbidities included body mass index (BMI), diabetes, smoking, chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), hypertension, dialysis, chronic steroid or immunosuppressant use, bleeding disorders, and American Society of Anesthesiologists (ASA) Classification. Univariate and multivariate analyses were then performed to identify risk factors associated with 30-day readmission. 14,339 patients met inclusion criteria and 6,507 (45.3%) had a hospital LOS less than or equal to 24 hours. The mean length of hospitalization was 1.95 ± 1.88 days, the average age was 69 ± 9.7 years old, and 56.9% of the patients were female. Following a risk adjusted multivariate analysis, increasing age (odds ratio [OR], 1.03, 95% confidence interval [CI], 1.02–1.03), ASA classification (OR, 1.50, 95% CI, 1.41–1.60), diabetes (OR, 1.69, 95% CI, 1.43–1.99), COPD (OR, 1.35, 95% CI, 1.16–1.57), CHF (OR, 2.67, 95% CI, 1.34–5.33), dialysis (OR, 2.47, 95% CI, 1.28, 4.77), history of a bleeding disorder (OR, 1.50, 95% CI, 1.20–1.88), or increasing operative time (OR, 1.01, 95% CI, 1.01–1.01) were identified as independent risk factors for hospital lengths of stay exceeding 24 hours. Male gender was identified as a protective factor for prolonged hospitalization (OR, 0.50, 95% CI, 0.46–0.53). This study identifies patient demographics, co-morbidities, and operative-relative risk factors that are associated with increased risk for a prolonged hospitalization following total shoulder arthroplasty. Female gender, increasing age, ASA classification, operative time, or a history of diabetes, COPD, CHF, or history of a bleeding disorder are risk factors hospitalizations exceeding 24 hours.
Malnutrition is an important consideration during the perioperative period and albumin is the most common laboratory surrogate for nutritional status. The purpose of this study is to identify if preoperative serum albumin measurements are predictive of infection following arthroscopic procedures. Patients undergoing knee, shoulder or hip arthroscopy between 2006–2016 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patients with an arthroscopic current procedural terminology code and a preoperative serum albumin measurement were included. Patients with a history of prior infection, including a non-clean wound class, pre-existing wound infection or systemic sepsis were excluded. Independent t-tests where used to compare albumin values in patients with and without the occurrence of a postoperative infection. Pre-operative albumin levels were subsequently evaluated as predictors of infection with logistic regression models. There were 31,906 patients who met the inclusion criteria. The average age was 55.7 years (standard deviation (SD) 14.62) and average BMI was 31.7 (SD 7.21). The most prevalent comorbidities were hypertension (49.2%), diabetes (18.4%) and smoking history (16.9%). The average preoperative albumin was 4.18 (SD 0.42). There were 45 cases of superficial infection (0.14%), 10 cases of wound dehiscence (0.03%), 17 cases of deep infection (0.05%), 27 cases of septic arthritis or other organ space infection (0.08%) and 95 cases of any infection (0.30%). The preoperative albumin levels for patients who developed septic arthritis (mean difference (MD) 0.20, 95% CI, 0.038, 0.35, P = 0.015) or any infection (MD 0.14, 95% CI 0.05, 0.22, P = 0.002) were significantly lower than the normal population. Additionally, disseminated cancer, Hispanic race, inpatient status and smoking history were significant independent risk factors for infection, while female sex and increasing albumin were protective towards developing any infection. Rates of all infections were found to increase exponentially with decreasing albumin. The relative risk of infection with an albumin of 2 was 3.46 (95% CI, 2.74–4.38) when compared to a normal albumin of 4. For each albumin increase of 0.69, the odds of developing any infection decreases by a factor of 0.52. This study suggests that preoperative serum albumin is an independent predictor of septic arthritis and all infection following elective arthroscopic procedures. Although the effect of albumin on infection is modest, malnutrition may represent a modifiable risk factor with regard to preventing infection following arthroscopy.
The aim of this study was to identify if perioperative outcomes were different in patients with cerebral palsy undergoing unilateral or bilateral hip reconstruction. All consecutive hip reconstructions for cerebral palsy performed by the senior author (FNT) within a tertiary-referral centre were identified between January 2012 and July 2016. Patients were stratified by age, gender, GMFCS and side of procedure. Length of surgery, pre- and post- operative haemoglobin, length of stay and immediate post-operative complications were measured.Purpose
Method
Patellofemoral joint is an important aspect of the tri-compartmental knee joint complex. Total knee arthroplasty (TKA) replaces the articulating surfaces of distal femur and proximal tibia, and often times the patella as well. Understanding the size relationship between the femur and patella bones can provide valuable information for new prosthesis design and biomechanical analysis. However, taking anthropometric measurements on a large population of patients or even cadaveric specimens could be a challenge. As a result, there are currently little quantitative data existing in the literature regarding the size relationship between TKA patient's femur and patella. This study attempted to attack this question using a novel statistical approach and a large TKA patient database. A multi-site clinical database operated by Exactech was used in this study. The database contains patient information of Optetrak TKA implant recipients from over 30 physicians in US, UK, and Colombia since 1995. Nine femoral implant sizes (0, 1, 2, 2.5, 3, 3.5, 4, 5 and 6) and six patellar implant sizes (26, 29, 32, 35, 38, 41 mm) were seen in these patients. Due to the low usage, femoral sizes 0 and 6 were excluded from this analysis. Taking primary TKA only, a total of 2,698 cases were included in this study. The size relationship between femoral implant and patellar implant was analyzed in this patient population. Gender effect was also examined.Introduction
Methods
A better understanding of the rate of improvement associated with aTSA and rTSA is critical to establish accurate patient expectations for treatment to reduce pain and restore function; more realistic patient expectations pre-operatively may lead to greater patient satisfaction post-operatively. To this end, this study quantifies the rate of improvement in outcomes of aTSA and rTSA using 5 different scoring metrics for 1641 patients with one platform shoulder arthroplasty system. 1641 patients (mean age: 69.3yrs) were treated by 14 orthopaedic surgeons using one platform shoulder system (Exactech, Inc). 729 patients received aTSA (65.3yrs; 384F/345M) for treatment of degenerative arthritis and 912 patients received rTSA (72.5yrs; 593F/319M) for treatment of CTA/RCT/OA. Each patient was scored pre-operatively and at various follow-up intervals (3 months, 6months, annually, etc) using the SST, UCLA, ASES, Constant, and SPADI metrics; active abduction, active forward flexion, and active/passive external rotation were also measured. 4439 total follow-up reports were analyzed (1851 and 2588 rTSA). Improvements in outcome using each metric score were calculated and normalized on a 100 point scale. The rate of improvement was analyzed using a 40 point moving filter treadline and with a 3rd order polynomial treadline over the entire range of follow-up.Introduction
Methods
Total knee arthroplasty (TKA) implant systems offer a range of sizes for orthopaedic surgeons to best mimic the patient's anatomy and restore joint function. From a biomechanical perspective, the challenge on the TKA implants is affected by two factors: design geometry and in vivo load. Larger geometry typically means more robust mechanical structure, while higher in vivo load means greater burden on the artificial joint. For an implant system, prosthesis geometry is largely correlated with implant size, while in vivo load is affected by the patient's demographics such as weight and height. Understanding the relationships between implant size and patients' demographics can provide useful information for new prosthesis design, implant test planning, and clinical data interpretation. Utilizing a manufacturer supported clinical database, this study examined the relationships between TKA patient's body weight, height, and body mass index (BMI) and the received implant size of a well-established implant system. A multi-site clinical database operated by Exactech, Inc. (Gainesville, FL, USA) was utilized for this study. The database contains patient information of Optetrak TKA implant recipients from over 30 physicians in US, UK, and Colombia since 1995. Nine implant sizes (0, 1, 2, 2.5, 3, 3.5, 4, 5 and 6) are seen in the database, while size 0 was excluded due to very low usage. Taking primary TKA only, a total of 2,713 cases were examined for patient's body weight, height, BMI, and their relationships with the implant size.Introduction
Methods
Cruciate Retaining (CR) and Posterior Stabilizing (PS) are two common types of total knee arthroplasty (TKA) surgeries. The CR approach preserves the posterior cruciate ligament (PCL) while the PS approach sacrifices it. Implant size selection during a TKA surgery is primarily driven by the patient's bone size, but could also be affected by surgery types due to the influence of the PCL. The objective of this study was to investigate the effect of TKA surgery type on implant size selection, based on the clinical database of a well-established commercial implant system. A clinical database operated by Exactech, Inc. (Gainesville, FL, USA) was utilized for this study. The database contains TKA patient information of Optetrak® implant recipients from over 30 physicians in the US, UK, and Colombia since 1995. Patient height was used as a control factor for comparison of surgery types, and categorized by every 10 cm (e.g., the “170 cm” category contains patients from 170 to 179 cm). Taking primary TKA only and body heights from 130 cm to 199 cm, a total of 2,677 cases were examined. No statistical difference exists on patients' gender, body weight, or BMI within every height category between the CR and PS groups. The femoral implant size and tibial insert thickness were compared between the two groups.Introduction
Methods
To determine the tensile forces across the knee extensor mechanism during walking, in simulated conditions of treatment. Gait analysis of six normal subjects was performed, with full weight bearing unilateral immobilisation of the knee during walking. Measurements were taken without then with a brace, unlocked then locked at 0°, 0-10°, 0-20° and 0-30° of flexion. Mean and maximum knee flexion angles were measured, followed by calculation of the mean and maximum forces across the extensor mechanism during loading, supporting and propulsion phases of gait.Aim
Methods
Bone marrow derived mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. Hypoxia has been shown to improve chondrogenesis in adult stem cells. In this study we characterised bone marrow derived stem cells and investigated the effects of hypoxia on gene expression changes and chondrogenesis. Adherent colony forming cells were isolated and cultured from the stromal component of bone marrow. The cells at passage 2 were characterised for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium under normoxic (20% oxygen) or hypoxic (5% oxygen) conditions for 14 days. Gene expression analysis, glycosoaminoglycan and DNA assays, and immunohistochemical staining were determined to assess chondrogenesis.INTRODUCTION
MATERIALS AND METHODS
Mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. We have previously demonstrated that the infrapatellar synovial fat pad is a rich source of mesenchymal stem cells and these cells are able to undergo chondrogenic differentiation. Although synovial fat pad derived mesenchymal stem cells may represent a heterogenous population, clonal populations derived from the synovial fat pad have not previously been studied. Mesenchymal stem cells were isolated from the infrapatellar synovial fat pad of a patient undergoing total knee arthroplasty and expanded in culture. Six clonal populations were also isolated before initial plating using limiting dilution and expanded. The cells from the mixed parent population and the derived clonal populations were characterised for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium for 14 days. Gene expression analyses; glycosoaminoglycan and DNA assays; and immunohistochemical staining were determined to assess chondrogenic responses.Introduction
Materials and Methods
Bone marrow derived mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. Hypoxia has been shown to improve chondrogenesis in adult stem cells. In this study we characterised bone marrow derived stem cells and investigated the effects of hypoxia on gene expression changes and chondrogenesis. Adherent colony forming cells were isolated and cultured from the stromal component of bone marrow. The cells at passage 2 were characterised for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium under normoxic (20% oxygen) or hypoxic (5% oxygen) conditions for 14 days. Gene expression analysis, glycosoaminoglycan and DNA assays, and immunohistochemical staining were determined to assess chondrogenesis.INTRODUCTION
MATERIALS AND METHODS
Mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. We have previously demonstrated that the infrapatellar synovial fat pad is a rich source of mesenchymal stem cells and these cells are able to undergo chondrogenic differentiation. Although synovial fat pad derived mesenchymal stem cells may represent a heterogenous population, clonal populations derived from the synovial fat pad have not previously been studied. Mesenchymal stem cells were isolated from the infrapatellar synovial fat pad of a patient undergoing total knee arthroplasty and expanded in culture. Six clonal populations were also isolated before initial plating using limiting dilution and expanded. The cells from the mixed parent population and the derived clonal populations were characterised for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium for 14 days. Gene expression analyses; glycosoaminoglycan and DNA assays; and immunohistochemical staining were determined to assess chondrogenic responses.Introduction
Materials and Methods
The aim of this study was to determine current practice in anterior cruciate ligament reconstruction amongst BASK members. This was an internet-based survey where members were invited to complete a questionnaire on ACL reconstruction. Of the 365 BASK surgeons performing ACL reconstruction, 241 completed the questionnaire (response rate 66%). 147(61%) of surgeons used both hamstring and patellar tendon grafts, 71(29%) used only hamstrings and 21(9%) used patellar tendon only. All surgeons used ipsilateral autograft. 157 (65%) used the transtibial technique for femoral tunnel placement with 80(33%) using the anteromedial portal technique. Of those using the anteromedial portal, the most common femoral fixation devices were the Endobutton (34%) and RCI screw (34%). Interference screw fixation (81%) was the most common tibial fixation in the same group of surgeons with the RCI screw being the most common (63%). 19% (45/241) of surgeons were performing double bundle ACL reconstructions in select cases. Hamstring femoral fixation was with a suspension device in 79% and interference screw in 18%. Of those using a suspension device the Endobutton was most common (48%) followed by Transfix (26%) and Rigidfix (19%). Tibial fixation was most commonly achieved by interference screw (57%) followed by Intrafix (30%). With patellar tendon graft the most popular femoral fixation was with an interference screw (66%) followed by suspension (34%). All surgeons used interference screw for tibial fixation. 90% of surgeons (217) allow immediate full weight-bearing as tolerated irrespective of fixation type with 8% delaying full weight bearing between 1 and 3 weeks. The results show the wide spread of variation in practice of ACL reconstruction. With recent renewed interest in a more anatomic placement of tunnels, the use of the anteromedial portal may continue to increase. With such a wide variation in techniques, grafts and fixation implants used, a register may help assess outcomes.
With numbers available, there were no differences between the groups with regard to change in KSS (p=0.38), ROM (p=0.42), mean postoperative anatomic alignment (5.78° vs. 5.50°, p=0.37), femoral angle (5.56° vs. 5.61°, p=0.84), or tibial angle (89.89° vs. 89.69°, p=0.46). There was a non-significant trend towards fewer outliers in the CASTKA group with respect to anatomic alignment (2.8% vs. 13.9%, p=0.09) and tibial angle (0% vs. 5.6%, p=0.46).
Patient charts and radiographs were reviewed. Statistical analysis was performed. Significant variables associated with patient anatomy, implant size and alignment were subsequently investigated in a computational model to evaluate tendofemoral contact.
We aim to create a set of reference data of commonly used scoring systems in the normal population, and to compare these results with published postoperative scores for commonly performed knee operations. This was a questionnaire-based study and a total of 744 questionnaires were sent out, of which 494 replies were received. Six scoring systems were addressed: Lysholm and Oxford Knee Scores, Tegner and UCLA activity scales and Visual Analogue Scales (VAS) for both pain and function. Data was collected into groups based on age (20–29, 30–39, 40–49, 50–59, 60–69, 70–79, 80–89 years). The reference data obtained was then compared to published postoperative scores for knee arthroplasty and ACL reconstruction, to assess whether these patients did indeed return to “normal”. The mean scores for sequential age groups (described above) were as follows: Oxford Knee Score – 13, 13, 14, 14, 17, 15, 17; Lysholm Knee Score – 96, 95, 92, 89, 89, 89, 79; Tegener Activity Scale – 6, 5, 5, 4, 4, 3, 3; UCLA Activity Scale – 8, 7, 7, 7, 6, 6, 5; VAS pain – 5, 8, 10, 9, 14, 12, 20; VAS function 96, 95, 90, 90, 86, 84, 84. Symptom based scoring systems (Oxford Knee Score, Lysholm) were independent of age whereas activity scores (Tegner, UCLA) decreased with age. There was no significant difference detected between scores in different sexes in the same age group. Compared to published scores in an age-matched population following TKR, the data obtained showed that patients do not return to normal scores following arthroplasty. Following ACL reconstructive surgery, activity scores were higher than compared to the data obtained from our population. Data generated from this study can be used as reference data and can play an important role in interpreting post-intervention scores following knee surgery.
Complex primary total knee replacements have been poorly reported in the literature We review all complex primary total knee replacement procedures at Stepping Hill Hospital. Patients underwent knee examination, knee scores, notes review and pre- and post-operative radiograph review. There were 29 patients with 36 knees that had a complex primary total knee replacement. Most frequent indications for surgery were osteoarthritis, rheumatoid arthritis or following trauma. Mean age at surgery 70 years. The prosthesis used were : 3 Stryker Kinemax; 32 De Puy PFC and one rotating hinge. Complex Primary Oxford knee score; preoperative mean 45 (range 33 to 57); postoperative mean 26 (range 14 to 53). NJR Total Knee Replacement Oxford knee score postoperative mean 30. Mean visual analogue scores; pain in the knee, mean 19; knee function, mean 77; outcome of the operation 76; satisfaction with the surgery 87. Mean length of hospital stay 13 days. Using the Knee Society Radiographic Scoring System, there were no signs that need to be monitored or signify failure. Seven patients were transfused postoperatively, four patients had minor wound problems, three required further surgery, two to washout the knee and exchange the polyethylene liner, one femoral plating to stabilise an osteotomy site. Long term complications : one above knee amputation for infection, one foot drop. Revision implants can be used in complex primary knee replacements, and pose technical difficulties but address various pathologies. The surgery is associated with an increased risk of complications and transfusion. Clinical scores at least match scores for routine total knee replacements, patient satisfaction is excellent.
What is the effect on the length of a procedure when a trainee is involved? What is the effect on the length of a list and the number of procedures performed on the list when a trainee is involved? What percentage of cases had trainee involvement for anaesthetics and surgery? Is this is statistically significant?
Among these cases, 71% were performed by senior trainees. The consultant’s log book data also suggested the similar trends. In all comparisions, time taken by trainees to perform surgeries were statistically significant. Trainee performed with consultant scrubbed versus consultant performed (P = <
0.0001), trainee performed with consultant in theatre versus consultant performed(P = 0.0318) and trainee performed with consultant scrubbed versus trainee performed with consultant in theatre (P = 0.002)
Among these cases, 71% were performed by senior trainees. The consultant’s log book data also suggested the similar trends. Statistically, trainee performed with consultant scrubbed versus consultant performed (P = <
0.0001), trainee performed with consultant in theatre versus consultant performed(P = 0.0318) and trainee performed with consultant scrubbed versus trainee performed with consultant in theatre (P = 0.002)
To counter this, training hospitals should be given financial incentives to train in surgery, or procedures performed by trainees should be priced differently to account for the time lost by training.
There is an ever-increasing clinical need for the regeneration and replacement of tissue to replace soft tissue lost due to trauma, disease and cosmetic surgery. A potential alternative to the current treatment modalities is the use of tissue engineering applications using mesenchymal stem cells that have been identified in many tissue including the infrapatellar fat pad. In this study, stem cells isolated from the infrapatellar fat pad were characterised to ascertain their origin, and allowed to undergo adipogenic differentiation to confirm multilineage differentiation potential. The infrapatellar fat pad was obtained from total knee replacement for osteoarthritis. Cells were isolated and expanded in monolayer culture. Cells at passage 2 stained strongly for CD13, CD29, CD44, CD90 and CD105 (mesenchymal stem cell markers). The cells stained poorly for LNGFR and STRO1 (markers for freshly isolated bone marrow derived stem cells), and sparsely for 3G5 (pericyte marker). Staining for CD34 (haematopoetic marker) and CD56 (neural and myogenic lineage marker) was negative. {BR}For adipogenic differentiation, cells were cultured in adipogenic inducing medium consisting of basic medium with 10ug/ml insulin, 1uM dexamthasone, 100uM indomethacin and 500uM 3-isobutyl-1-methyl xanthine. By day 16, many cells had lipid vacuoles occupying most of the cytoplasm. On gene expression analyses, the cells cultured under adipogenic conditions had almost a 1,000 fold increase in expression of peroxisome proliferator-activated receptor gamma-2 (PPAR gamma-2) and 1,000,000 fold increase in expression of lipoprotein lipase (LPL). Oil red O staining confirmed the adipogenic nature of the observed vacuoles and showed failure of staining in control cells. Our results show that the human infrapatellar fat pad is a viable potential autogeneic source for mesenchymal stem cells capable of adipogenic differentiation as well as previously documented ostegenic and chondrogenic differentiation. This cell source has potential use in tissue engineering applications.
Templating of preoperative radiographs is routinely recommended prior to knee arthroplasty. We performed this study to assess the reproducibility and accuracy of the templates for three commonly used knee implants (PFC, Kinemax, Scorpio). Six lower limb surgeons templated 10 patients for each of the three designs. The inter and intra-observer reliability and accuracy was calculated. There was marked variation in the reliability of the templating with the tibial insert scoring better than the femoral and the Kinemax being the most reproducible of the three. In general, the intra-observer scores (κ= 0.57–0.81) were better than the inter-observer ones (κ= 0.21–0.60). The Scorpio was the most accurately templated of the three implants, with the percentage correlating with what was actually implanted ranging from 55–62% for the femur and 72–75% for the tibia, with no templated sizes more than 1 size different from the actual implant. The other implants ranged from 38–42% for the femur and 53–58% for the tibia with both having up to 3% more than 1 size difference from the actual implant. We believe that the use of templating in total knee arthroplasty should be interpreted with caution and we urge the development of more accurate prosthesis sizing techniques.
Patella and extensor mechanism injuries are common injuries and are generally managed with some degree of immobilisation and partial weight bearing to facilitate healing. The aim of this project was to determine the type of immobilisation or splintage during partial weight bearing that results in minimal forces acting through the extensor mechanism. Gait analysis studies were performed on eight healthy male subjects mobilising partially weight bearing. Measurements were taken for six types of immobilisation: locked at 0, 10, 20, 30 degrees and unlocked in an orthotic knee brace, and without a brace. The ground reaction force, knee joint angle and the knee flexion moment were measured using Qualisys Track Manager and Visual 3D Software. The extensor mechanism moment and the extensor mechanism force were calculated using static equilibrium equations and documented data. A one-way analysis of variance statistical test was performed to determine the statistical significance of the differences between the six types of immobilisation. There was a direct relationship between the knee flex-ion angle and the extensor mechanism force. The extensor mechanism force at 0 degrees of immobilisation was significantly lower than that for 20 and 30 degrees (p<
0.05). The increase in the extensor mechanism moment arm with increasing knee flexion was not suf-ficient to offset the increase in the extensor mechanism force caused by the increase in the knee flexion moment. The results also showed that the knee flexion angle does not always correspond with the angle set at the knee brace; however they did exhibit a direct relationship. These results have important implications for the management of patients with patella and extensor mechanism injuries. The results suggest that improvements in knee brace design to allow 0 degrees of knee flexion, rather than the 10 degrees as seen in this study, are likely to result in significantly reduced extensor mechanism tensile forces.
At six weeks and three months, KT-1000 side-to-side differences between the groups are not statistically significant (student-t test, p=0.87 and p=0.34, respectively). In clinical results at six months, tibial fixation with Bioscrew XtraLok has significantly decreased laxity compared to the Intrafix device (p=0.017). This prospective, randomized clinical comparison of tibial fixation in hamstring ACL reconstruction evaluated mechanical results (laxity) between BioScrew XtraLok® (Linvatec, Largo, FL) and Intrafix® (Mitek Products, Norwood, MA) at six months. After Ethics Review Board approval and sample-size calculation, one hundred and three sequential patients undergoing ACL reconstruction were recruited. Inclusion criteria were: absence of other ligamentous injury or previous knee surgery, and a normal contralateral knee. After drilling tunnels, patients were allocated to a study arm (XtraLok® or Intrafix®) by a computer-generated randomization table. In all patients, EndoButton® (Smith &
Nephew, Andover, MA) was used for femoral fixation and the Mitek tensioner was employed. The patients were assessed with KT-1000 arthrometer manual maximum measurements taken at six weeks, three and six months post-operatively by independent clinicians. Mean measurements between the two groups were compared using the student-t test at the above intervals. At six months, eighty-seven of one hundred and three (84%) patients were available for follow-up; 43 XtraLok (XL), and forty-four Intrafix (IF). There was no significant difference between groups in mean age and gender. KT-1000 arthrometer side-to-side differences at six weeks were 1.04mm (XL) versus 1.14mm (IF), and 0.96mm (XL) versus 1.38mm (IF) at three months. At these intervals, differences between the groups are not statistically significant (p=0.87 and p=0.34, respectively). At six months, KT-1000 side-to-side difference was 1.26mm (XL) versus 2.41mm (IF), which is statistically significant (p=0.017). In clinical results at six months, ACL fixation with Bioscrew XtraLok shows decreased laxity compared to the Intrafix device.
During Anterior Cruciate Ligament reconstruction, using bone- patellar tendon- bone graft, debris can accumulate in the joint. We assessed incidence and potential for complications, described the radiographic appearance and defined the natural history of these intrarticular debris in 50 consecutive reconstructions. The records and radiographs of 50 consecutive cases were reviewed. A stripe of radio-opaque material, resembling a comma, termed the “comma” sign, was noted behind the lateral femoral condyle on the early postoperative radiographs of 40 of the 50 cases. There was no statistically significant difference in loss of knee motion at six, twelve, twenty- six and fifty- two weeks postoperatively (P>
0.50) between the patients presenting the radio-opacity and those without it. A second set of radiographs was taken in 12 patients between 3 and 18 months postoperatively, revealing that this radio- opaque material was visible in 1 case only. No correlation was found between presence of radio- opacities and duration of pain, effusion, analgesia requirement, discharge timing, time to driving and time to work. A protocol of postoperative early weight- bearing mobilisation had been followed in all cases which may have played a role in promoting the faster dissolution of the debris.
Periarticular fractures of the proximal tibia are some of the most difficult fractures to manage as open reduction and internal fixation of the fractures is plagued with complications such as non-union, delayed union, infection and post-traumatic osteoarthritis. We evaluated the results of 16 consecutive periarticular tibial fractures stabilised with the AO hybrid fixator using the Oxford Knee Score, American Orthopaedic Foot and Ankle Score (AOFAS) and X-rays of the tibia. Two patients were lost to follow up and 1 patient refused to take part in the study whose latest radiographs showed grade 4 degenerative changes. The mean follow up was 34 months (range 12 to 57 months) and the mean age was 50 years. All fractures were closed and were graded as either Schatzker 5 or 6. The fixator was applied for an average of 12 weeks. The mean Oxford Knee score was 27.2/60 (mild to moderate knee arthritis) and the mean AOFAS was 71.9/100. There was no significant malunion however 37.5% had developed radiological evidence of grade 3 or 4 post-traumatic osteoarthritis with one requiring a total knee replacement. Forty four percent of patients developed a complication with pin site infection being the commonest complication and 25% required further surgery. There were 2 nonunions with one requiring a fibular osteotomy, which subsequently united. Eighty eight percent of patients were satisfied with the procedure while 80% would recommend the procedure if required in future. From our study we feel that hybrid fixation of proximal periarticular tibial fractures is satisfactory however preoperative counselling regarding complications and the possible need for further surgery must be emphasised to the patient prior to embarking on this type of fixation.
The technique of arthroscopic decompression of patellar tendonitis was first undertaken in 1990. We report the 10 year experience of using this technique. Patients presenting with this condition were subjected to clinical, radiological and MRI assessment. The procedure was undertaken if the symptoms continued to be significant despite non-operative treatment. The procedure used a Dyonics shaver. The fat pad was elevated from the bare area of the patella to expose the non-articular inferior pole of the patella. The tendon fibres were then elevated from the anterior surface of the inferior pole, and the 5mm tip of the patella was excised taking particular care to ensure that the full AP thickness was removed. Seventy three knees underwent surgery with a minimum of one year follow up, in four cases a simultaneous bilateral procedure was performed and in 11 cases previous surgery had been performed elsewhere. The average age was 33 years, 64 of the cases were male. The average duration of symptoms was 20 months and all patients had undergone non-operative treatment prior to the index procedure for an average duration of 10 months. The average duration of follow up was 49 months. All patients experienced a significant improvement in the clinical grade of symptoms and function with 95% of the 62 primary cases resulting in a good or excellent result. The average time to return to work and driving was 2 weeks and to sport was 9 weeks. In the 11 revision cases, 9 (81%) were improved and 6 (55%) had a good result. The results of arthroscopic decompression for patellar tendonitis are superior to the other reported techniques. We conclude that excision of the inflammatory nodule and fat pad in this condition is unnecessary, other than to obtain visualisation of the inferior pole of the patella. The success of this procedure supports the suggestion that this condition is produced by a compression of the tendon and is best treated by decompression of the inferior patella pole.
We report our experience of four initial cases of mosaicplasty using large plugs in four cases and subsequently fourteen cases using the OATS technique and large grafts. The average size of the articular lesion was 1.7 sq cm with a range of 1–3 sq cm. The average number of grafts used was 2.3 with a range of 1.5. The average size was 9 mm with a range of 4–10 mm. Including a poor result due to infection, pain was only found in three patients on activity (17%). The Tegner score and the IKDC score improved significantly. The initial four cases of mosaicplasty resulted in two cases having donor site pain and crepitus which required a lateral release. Using the OATS technique reconstructing the donor site no further cases of pain and crepitus occurred. On MRI imaging, the recipient site was congruous, intact and appeared functional and only one patient demonstrated protuberance of the articular cartilage (1mm). Recipient site marrow oedema, fluid accumulation or kissing tibial signals were not significant features. The donor site articular cartilage was congruent in 5 patients and homogeneously isointense in 6 out of 7 patients. We have modified the technique and used osteochondral transplantation to treat isolated articular cartilage defects of 1–3 sq cm in area, using a mini open technique and multiple large grafts, avoiding graft impaction and with reconstruction of the donor site. This technique has resulted in an 89% success rate at an average of 2.5 years post operatively. Eighty three per cent of patients were able to return to recreational sports. MRI follow up has shown no cause for concern and demonstrates incorporation of all the grafts. The success reported in this study is higher than reported elsewhere but this may reflect the use of the modified technique.
The clinical implication: ACL tears should be treated initially conservatively since in a small percentage of patients, the ACL tear can heal.
We dissected 105 cadaveric shoulders to study the origin of the tendon of the long head of biceps, and examined histologically the interrelationship between the tendon, the supraglenoid tubercle and the superior labrum of the glenoid. In all specimens approximately 50% of the biceps tendon arose directly from the superior glenoid labrum with the remainder attached to the supraglenoid tubercle. The main labral origin was from the posterior labrum in more than half of the specimens, and in a quarter this was the only labral attachment. On the basis of the biceps attachment to the anterior or posterior labrum, we distinguished four types of origin. These normal anatomical variations are significant for arthroscopic diagnosis and may help to explain the various patterns of injury seen in partial or complete detachment of the tendon, the labrum or both.
The viability of three incisions for knee arthroplasty were analysed by transcutaneous estimation of the skin oxygen tension. Wound viability was found to be significantly reduced following knee arthroplasty. The lateral wound edge is more hypoxic than the medial, but there were no significant differences between the three incisions.
Antibiotic levels in bone and fat were measured in patients undergoing knee replacement to determine the time that should elapse between intravenous injection and tourniquet inflation. The tissue levels increased progressively with time, and there was wide variation in absorption rate between patients and between the two cephalosporins assessed. Five minutes should probably be left between systemic injection and inflation of the tourniquet, though two minutes may be long enough for drugs which are rapidly absorbed.
A randomised prospective trial was undertaken of antibiotic prophylaxis given at various intervals before inflation of the tourniquet for arthroplasty of the knee. Cefuroxime assays of bone and subcutaneous fat from samples collected throughout the operation demonstrated that an interval of 10 minutes was necessary to obtain adequate prophylaxis. Improvement in the timing of antibiotic prophylaxis may result in a reduction in the incidence of infection.
Early mobilisation after arthroplasty of the knee sometimes results in wound breakdown. The two commonly used incisions, the anterior midline and the medial parapatellar incisions, were compared in order to determine which had the best potential for wound healing. Study of the cleavage lines around the knee demonstrated that the medial parapatellar incision lies parallel to the lines, whilst the anterior midline incision lies perpendicular to them. In addition, the medial parapatellar wound was found to be subjected to significantly less tension during flexion; after arthroplasty it can be expected to heal faster and to be less liable to disruption during early mobilisation.
Atlanto-axial rotatory fixation is one of a spectrum of rotatory abnormalities of the atlanto-axial joint. Rotatory fixation without anterior displacement of the atlas (Type I) has been reported in only a few cases in which there has been a prolonged interval between injury and diagnosis. The majority of these cases eventually required cervical fusion for persistent deformity or instability. Two cases are presented in which this diagnosis was made early with the aid of rotated odontoid radiographs, tomography and computerised axial tomography. Treatment by a short period of halter traction achieved reduction and early return of function. The authors conclude that early recognition and treatment of this rare condition may prevent the subsequent deformity and instability for which cervical fusion has been required.
In order to define the predisposing factors and outcome of infected arthroplasty of the knee, a retrospective analysis of a consecutive series of 471 knee arthroplasties was performed. There were 23 cases of superficial wound infection and 25 of deep infection. Superficial wound infection alone resulted in a painfree gait, with little limitation of movement. Rheumatoid arthritis, the use of constrained prostheses and the presence of a superficial wound infection, all predisposed to deep infection. Deep infection was eradicated by long-term antibiotics in only two patients in whom skin cover was successfully provided by a gastrocnemius musculocutaneous flap. Excision of a sinus track, wound debridement and exchange arthroplasty were universally unsuccessful. Arthrodesis, however, in 11 out of 12 cases, provided the painfree gait these patients desire.