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Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 82 - 82
1 Mar 2009
Mir X Font J Monegal A Santana F Doreste J
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Introduction. Prospective study based on professional sportsmen who affected from Chronicle Compartmental Syndrome in forearm and its treatment. Material and methods. 32 Chronicle Compartmental Syndrome in forearm were studied in 24 patients. Our selection was composed by 16 men and 8 women. In 8 of our cases both forearms were operated. The age range was from 17 to 33 years of age. Their sportive activity included: 20 professional motorcyclists, 2 wind-surfers and 2 mountainbikers. To demonstrate evidence of Chronicle Compartmental Syndrome we performed a diagnostic test based on the measure of the intracompartmental pressure after stimulating their usual sportive activity. We considered a positive test when the measured an IMP> 15 mmHg after effort. We also performed a dynamometric of their grip and strength of the thumb-index forceps before and after surgery. Results. All 24 patients presented clinical and tests compatible with Chronicle Compartmental Syndrome in forearm during effort activities which reached severe range due to loss of sensibility and propioception. - From 15 to 20 mmHg of IMP after effort, 8 cases. - From 20 to 30 mmHg of IMP after effort, 11 cases. - Over 30 mmHg of IMP after effort, 13 cases. Minimal invasive surgery based on fasciotomy was performed to release compartmental pressure in flexor and extensor compartments of the forearm. Conclusions. We can conclude that after fasciotomy most of our patients improve either clinically and diagnostic tests results, without strength loss, and are able to return to their usual activity completely recovered in a short period of time


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 245 - 246
1 Sep 2005
Dailiana Z Varitimidis S Rigopoulos N Hantes M Karachalios T Malizos K
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Introduction: Suppurative conditions in closed cavities/tunnels require surgical drainage and irrigation for elimination of infection. The purpose of this study is to evaluate the pattern of extension of infections in hand compartments and the necessity for intraoperative and continuous postoperative catheter irrigation. Material and Methods: Compartmental infections of the hand and wrist (CIHW) were diagnosed in 42 consecutive patients involving the flexor tendon sheaths (pyogenic flexor tenosynovitis) (28); the tip (3); the carpal tunnel (2); or extended to multiple compartments including the above mentioned and the thenar, midpalmar, web and Parona’s (9). Three patients had diabetes mellitus, 2 suffered from bites, 15 had penetrating injuries and 7 were working with animals or meat products. Fifteen were previously treated in other centers. After meticulous clinical evaluation to define all the involved compartments, all patients were treated with drainage of the respective compartments, sheath irrigation and appropriate antibiotics, whereas continuous postoperative catheter irrigation was used in 24. Hand therapy started the third postoperative day. Results: Mean follow-up time was 20 months. The most common pathogen was S. aureus (14 patients) whereas cultures were negative in 15. Three patients received additional fungal treatment. Results were excellent or very good in 25 hands and good in 12 regaining full or near full ROM. Recurrence of infection in 4 (that were initially treated inadequately in other centers or had intraoperative sheath irrigation without postoperative continuous irrigation) necessitated a revision of the procedure with extensive debridement and continuous postoperative irrigation. Finally, 1 patient developed complex regional pain syndrome. Conclusions: A high index of suspicion and profound knowledge of the anatomy is essential for early diagnosis and prompt surgical treatment of CIHW. Initially «benign» infections often extend in multiple compartments of the hand as a result of inadequate initial treatment. Intraoperative irrigation is not always adequate for the resolution of infection, especially in neglected cases or cases with underlying conditions. Early surgical debridement of all the involved compartments in combination to continuous postoperative irrigation, administration of appropriate antibiotics and precocious onset of hand therapy is the treatment of choice for these potentially debilitating, infectious conditions of the hand


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 449 - 449
1 Sep 2009
Carbonell PG Fernández PD Ortuño JL Trigueros AP
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Spastic muscles show permanent contraction but also paradoxical muscular weakness. Compartmental muscular pressure in normal subjects oscillates between 0 and 5 mmHg. To study compartmental pressure in the posterior superficial compartment of the leg in children with spastic paralysis, to identify its variations after a percutaneous tenotomy of the Achilles tendon, and to find any possible connection with arterial pressure or weight. Twelve patients who had undergone a percutaneous tenotomy of the Achilles tendon were studied. Six of them were tetraplegic and three hemiplegic, with bilateral and unilateral tenotomies respectively. The following variables were taken into consideration: age, weight, systolic and diastolic arterial pressure and pressure of the superficial compartment of the leg, both pre- and post- tenotomy. The measurement of the compartmental pressure was taken using an automatic calibration monitor with an error of measure of ± 1 mmHg. Statistics: descriptive, non-parametric tests (Wilcoxon, Kruskall- Willis). The average age was 9.3 years old, 11 in men and 7.5 in women. 89.5% of the total population was male and 10.5 % female. The average weight was 27.2 Kilograms, 28.1 Kg. in men and 20.5 Kg. in women. Systolic pressure was 94.1 mmHg and diastolic pressure 41.3 mmHg. Pre-tenotomy compartmental pressure was 12.1 mmHg and 7.9 mmHg post-tenotomy, decreasing 34.5 % (p= 0.08, N.S.). Systolic pressure had no relation to pre-tenotomy (r = −0.16) o post-tenotomy (r = −0.13) compartmental pressure. Diastolic pressure had no relation either (p =0.2 and r=−0.36), respectively. The pressure of the superficial compartment of the leg is higher than normal in spastic patients, decreasing, although not significantly, after a percutaneous tenotomy of the Achilles tendon is performed


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 297 - 297
1 Jul 2011
Ardolino A Zeineh N O‘Connor D
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Background: Chronic compartment syndrome is well recognised. Patients present with exercise-induced pain, relieved by rest. The condition is caused by increased intra-compartmental pressure due to inadequate muscle/fascial compartment size. Cases of forearm chronic compartment syndrome are sporadic. Previous published case series affecting the upper limb have not used compartment pressure monitoring to aid diagnosis. In our chronic compartment pressure monitoring clinic we confirmed the diagnosis of four cases. Following these diagnoses a review of the literature showed that there was no definition of normal pre or post exercise pressure for the upper limb.

Aim: Acknowledging that diagnosis of forearm chronic compartment syndrome is largely based on clinical presentation supported by an ever increasing use of hand-held compartment pressure monitors, we felt it was important to establish what represented the normal pre and post exercise pressures in asymptomatic normal individuals to give a baseline upon which perceived raised pressures can be calculated against.

Methods: Ethical approval was obtained from Dorset Research and Ethics Committee. 41 participants underwent compartment pressure measurements of the superficial flexor and extensor compartments of the forearm before and five minutes following exercise. A Stryker intracompartmental pressuremonitor was used.

Results: Normal ranges for pre-exercise extensor compartment (2–27mmHg, CI 18.8–25.2mmHg), post-exercise extensor compartment (2–24mmHg, CI16.8–22.8mmHg), pre-exercise flexor compartment (1–19mHg, CI 13.3–17.4mmHg)) and post-exercise flexor compartment (0–19mmHg, CI 16–21.4) pressures were established. No significant difference was found between pressures before and after exercise (extensor pressures; p=0.41, flexor pressures; p=0.21). There was a significant difference between sexes (extensor pressures; p=0.04, flexor pressures; p=0.008)

Discussion: This study has established a significant difference in normal forearm compartment pressures between sexes. A normal reference range of forearm compartment pressures to aid diagnosis of chronic compartment syndrome has been determined. This can also be useful in diagnosing acute compartment syndrome.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_II | Pages 179 - 179
1 May 2011
Ardolino A Zeineh N O’Connor D
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Background: Chronic compartment syndrome is well recognised. Patients present with exercise-induced pain, relieved by rest. The condition is caused by increased intracompartmental pressure due to inadequate muscle compartment fascial size. Cases of forearm chronic compartment are sporadic. Previous published case series affecting the upper limb have not used compartment pressure monitoring to aid diagnosis. In our chronic compartment pressure monitoring clinic we confirmed the diagnosis of four cases. Following these a review of the literature showed that there was no definition of normal pre or post-exercise pressure for the upper limb.

Aim: This study aimed to establish the normal pre and post-exercise forearm pressures in asymptomatic normal individuals to give a baseline upon which perceived raised pressures could be calculated against.

Methods: Ethical approval was obtained from Dorset Research and Ethics Committee. 41 participants underwent compartment pressure measurements of the superficial extensor and flexor forearm compartments before and after five minutes of exercise. A Stryker intracom-partmental pressure monitor was used.

Results: Normal ranges for pre-exercise extensor compartment (2–27mmHg, upper CI 18.8–25.2mmHg), post-exercise extensor compartment (2–24mmHg, upper CI 16.8–22.8mmHg), pre-exercise flexor compartment (1–19mmHg, upper CI 13.3–17.4mmHg) and post-exercise flexor compartment (0–19mmHg, upper CI 16–21.4mmHg) pressures were established. No significant difference was found between pressures before and after exercise (extensor pressures; p=0.41, flexor pressures; p=0.21). There was a significant difference between sexes (extensor pressures; p=0.04, flexor pressures; p=0.008)

Conclusion: This study has shown a significant difference in normal forearm compartment pressures between sexes. No difference between pre and post-exercise pressure could be established. A normal reference range of forearm compartment pressures to aid diagnosis of chronic compartment syndrome has been determined. This may also prove useful in aiding the diagnosis of acute forearm compartment syndrome.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_5 | Pages 1 - 1
1 Mar 2017
Meere P Walker P Salvadore G
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Introduction

Soft tissue balancing in total knee arthroplasty surgery may prove necessary to elevate patient satisfaction and functional outcome beyond the current fair average. A new generation of contact load sensors embedded in trial tibial liners provides quantification of loads, direction, and an indirect assessment of ligamentous tension. With this technology, quantified intra-operative balancing may potentially restore compartmental load distribution to a more physiological and functional degree.

Objective

1). To define a clinically useful target zone for balancing of the soft tissue envelope of knees at the time of surgery using numerical data from load sensors in tibial liner trial components. 2). To validate the boundaries of the target zone on a medial v. lateral contact load scatterplot with PROMs


Bone & Joint Open
Vol. 2, Issue 8 | Pages 638 - 645
1 Aug 2021
Garner AJ Edwards TC Liddle AD Jones GG Cobb JP

Aims

Joint registries classify all further arthroplasty procedures to a knee with an existing partial arthroplasty as revision surgery, regardless of the actual procedure performed. Relatively minor procedures, including bearing exchanges, are classified in the same way as major operations requiring augments and stems. A new classification system is proposed to acknowledge and describe the detail of these procedures, which has implications for risk, recovery, and health economics.

Methods

Classification categories were proposed by a surgical consensus group, then ranked by patients, according to perceived invasiveness and implications for recovery. In round one, 26 revision cases were classified by the consensus group. Results were tested for inter-rater reliability. In round two, four additional cases were added for clarity. Round three repeated the survey one month later, subject to inter- and intrarater reliability testing. In round four, five additional expert partial knee arthroplasty surgeons were asked to classify the 30 cases according to the proposed revision partial knee classification (RPKC) system.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXV | Pages 259 - 259
1 Jun 2012
Yildirim G Walker P Conditt M Horowitz S Madrid I
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Introduction

The MAKO Surgical Rio Robotic Arm utilizes the pre-op CT images to plan positioning of the uni-condylar and patella-femoral components in order to achieve the most desirable kinematics for the knee joint. We hypothesize that the anatomic matching surfaces and the cruciate retaining design of the Restoris knee will best replicate normal knee kinematics. We tested the healthy cadaveric knee versus the MAKO knee and the most common TKR designs in order to evaluate and compare the kinematic properties.

Methods

Six healthy male left knees were dissected to leave only the knee capsule and the quadriceps tendon intact. The femur and the tibia were cut 20cm from the joint line and potted with cement into a metal housing. The knee was attached to a crouching machine capable of moving the knee joint though its normal human kinematics from extension to maximum flexion, validated in previous studies. Forces applied to the quadriceps tendon allowed the knee to flex and extend physiologically, and springs attached to the posterior were substituted as the hamstrings at a rate of half the force exerted by the quadriceps as shown in the literature. Three dimensional visual targets attached to the bones were tracked by computer software capable of recreating the positions of the bones in any given flexion angle. A cruciate retaining and posterior stabilized TKR design were chosen to represent the TKRs most commonly available in the market today. The intact knee, MAKO implanted knee, CR and PS TKR designs were tested in sequence on the same specimens. The computer software analyzed the normal distance between the bone surfaces and plotted the locations of contact which could then be quantitatively compared for each given scenario [Fig. 1].


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 416 - 417
1 Sep 2009
Walton M Newman J
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Objectives: This study aims to assess the psychological profile of patients prior to total knee replacement, medial unicompartmental knee replacement and patellofemoral joint replacement and determine its effect on outcome.

Methods: 113 patients were identified (41 TKR, 37 UKR and 35 PFJR). All patients had mental health assessed preoperatively using SF-12. From the 12 questions a mental and a physical summary score can be calculated (MCS and PCS). The reduced WOMAC score was used pre-operatively to assess knee function and symptoms and then recorded at 8 and 24 months post-operation to assess outcome.

Results: 54% of the patients had pre-operative psychological distress. There was no statistically significant difference demonstrated between them mean MCS scores between the three operation groups. Pre-operative MCS had a significant effect such that increasing psychological distress lead to a worse twenty-four month outcome (p = 0.016). The effect of MCS is most marked in postoperative pain levels (p = 0.008) compared to function (p = 0.016). The mean 24-month rWOMAC in the severely distressed group (MCS< 40) was 28.4 compared to 17.4 in the psychologically well group (MCS> 60).

Conclusions: Pre-operative mental function prior to knee arthroplasty may provide useful information to guide patients as to their expected outcome in the consent process. Those patients with a very high mental component may be counseled to that although their distress is likely to improve with surgery, their eventual outcome may be worse. The effect of MCS may however only be clinically relevant in those patients with severe mental symptoms.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XLI | Pages 42 - 42
1 Sep 2012
Hooper G Gilchrist N Frampton C Maxwell R Heard A Mcguire P
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Bone mineral density (BMD) and bone mineral content (BMC) have not been previously assessed in unicompartmental knee replacement (UKR). We studied the early bone changes beneath the uncemented Oxford medial UKR. Our hypothesis was that this implant should decrease the shear stresses across the bone-implant interface and result in improved BMD and BMC beneath the tibial component.

Using the Lunar iDXA and knee specific software we developed 7 regions of interest (ROI) in the proximal tibia and assessed 38 patients with an uncemented Oxford UKR at 2 years. We measured the replaced knee and contralateral unreplaced knee using the same ROI and compared the BMD and BMC. The initial precision study in 20 patients demonstrated high precision in all areas.

There were 12 males and 16 females with an average age of 65.8 years (46–84 years). ROI 1 and 2 were beneath the tibial tray and had significantly less BMC (p=0.023 and 0.001) and BMD (p=0.012 and 0.002). ROI 3 was the lateral tibial plateau and this area also had significantly less BMC (p=0.007) and BMD (p=0.0001). ROI 4 and 5 immediately below the tibial keel had no significant change. These changes were independent of gender and age.

These results were surprising in that the universal loss of BMC and BMD suggested that bone loading of the proximal tibia was not improved even after a UKR. The better BMD and BMC adjacent to the keel confirms other studies that show improved bone in-growth around keels and pegs in the uncemented tibial component. A prospective longitudinal study has been developed to compare BMD and BMC changes over time to see whether these changes are dynamic.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_3 | Pages 86 - 86
1 Apr 2018
Van Rossom S Khatib N Van Assche D Holt C Jonkers I
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Healthy cartilage is essential for optimal joint function. Although, articular cartilage defects are highly prevalent in the active population and might hamper joint function, the effect of articular cartilage defects on knee contact forces and pressures is not yet documented. Therefore, the present study compared knee contact forces and pressures between patients with a tibiofemoral cartilage defect and healthy controls. This might provide additional insights in movement adaptations and the role of altered loading in the progression from defect to OA. Experimental gait data was collected in 15 patients with isolated articular cartilage defects (8 medial-affected, 7 lateral-affected) and 19 healthy asymptomatic controls and was processed using a musculoskeletal model to calculate contact forces and pressures. Differences between medial-affected, lateral-affected and controls were evaluated using Kruskal-Wallis tests and individually compared using Mann-Whitney-U tests (alpha <0.05). The lateral-affected group walked significantly slower compared to the healthy controls. No adaptations in the movement pattern that resulted in decreased loading on the injured condyle were observed. Additionally, the location of loading was not significantly affected. The current results suggest that isolated cartilage defects do not induce changes in the knee joint loading pattern. Consequently, the involved condyle will be equally loaded, indicating that a similar amount of force should be distributed over the remaining cartilage surrounding the articular cartilage defect and may cause local degenerative changes in the cartilage. This in combination with inflammatory responses might play a key role in the progression from articular cartilage defect to a more severe OA phenotype.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 344 - 344
1 Sep 2005
Hollinghurst D Stoney J Ward T Robinson B Price A Gill H Beard D Dodd C Newman J Ackroyd C Murray D
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Introduction and Aims: Single compartmental replacement procedures are increasingly preferred over total knee replacement (TKR) for single compartment osteoarthritis of the knee joint. Theoretically, reduced disruption of the native joint should produce more normal kinematics. This study aimed to describe and compare the sagittal plane kinematics of four different, commonly used devices.

Method: Four groups of patients who had undergone successful single compartment replacement at least two years previously were recruited. Fifteen following Oxford medial UKA, 12 following medial St Georg Sled UKA, five following Oxford lateral UKA, and 12 following Avon PFJ replacement. Patients performed flexion/extension against gravity, and a step-up during video fluoroscopy. The Patellar Tendon Angle (PTA), the angle between the long axis of the tibia and the patella tendon, was obtained as a function of knee flexion. This relationship provides indication of sagittal movement between femur and tibia through range and has been validated as a reliable measure of joint kinematics.

Results: The kinematic profile for each group was compared to that of the profile for 12 normal and 30 TKR (AGC) knees. All three tibiofemoral devices produced knee kinematics similar to the normal knee. The PTA was found to have a linear relationship to flexion angle, decreasing with increasing knee flexion angle. No such linear relationship exists for the TKR joint, which display abnormal kinematics. The PF device also reflected similar trends to that for normal knees except that the PTA was moderately increased throughout the entire range of flexion (three degrees).

Conclusion: In contrast to TKR, all single compartmental knee replacements provided kinematics similar to the normal joint. The kinematic pattern of the PFJ replacement may be of most interest as the observed increase in PTA through range could influence patello-femoral contact forces


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 385 - 385
1 Jul 2011
Malal JG Deshpande S
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Oxford medial uni compartmental knee replacement is a common and widely accepted procedure that relies on accurate positioning and alignment of the implants for optimal outcome and longevity. Posterior slope of the tibial base plate has been shown to be an important factor affecting long term survivorship.

The aim of the study was to evaluate whether navigation increased the accuracy of Oxford knee replacements using the posterior slope of the tibial component as an index measure.

The posterior slope of tibial trays from 58 sequential Oxford medial unicondylar knee replacements over a two year period was checked on standard lateral x-rays against the recommended range.

There were 12 cases in the navigated and 46 in the conventional group across six Orthopaedic firms. The mean posterior slope for navigated and conventional implantations was 4.75 and 3.3 degrees respectively with the difference not being statistically significant. However, when considering the data for low volume surgeons, the mean posterior slope with and without navigation was 4.75 and 1.83 degrees respectively which was significant with a p value of 0.017. Navigation was also found to significantly decrease the chance of implanting the knee with the posterior slope outside the acceptable range (p=0.024). In both analyses the navigated cohort had a narrower data spread and fewer outliers compared to the conventional group. No other factors were found to significantly correlate with the posterior slope.

The study suggests that navigation might help low volume surgeons in increasing the accuracy and decreasing the incidence of extreme variations from the desirable range of implant positioning for unicompartmental knee replacements.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_9 | Pages 37 - 37
1 May 2016
Meere P Schneider S Borukhov I Walker P
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Introduction

The mechanical classical method of knee surgical instrumentation by alignment is based on built-in compromises and is considered insufficient to ensure consistent success. Soft tissue balancing is thus now seen as necessary for optimal functional outcomes and patient satisfaction. (Matsuda 2005, Winemaker 2002). The authors have previously demonstrated that balancing can be achieved through specific strategic moves. In this study, the goal was to determine the efficacy of a given surgical algorithm and to define predictors of improved outcome. The surgical target is equilibrium of contact loads. The mechanical axis remains in neutral, however subtle variation in the joint line obliquity and posterior slope are tolerated within the literature established boundaries of +/− 3 degrees and less than 10 degrees respectively.

Methods

Data was obtained from 101 consecutive primary procedures from a single surgeon (PAM) using a PCL-retaining device. For all cases the testing methodology consisted of a sag test, heel push, drawer testing at 90 degrees, and varus-valgus laxity testing at 10 degrees of flexion. Instrumented tibial trials were used to measure the contact forces on the lateral and medial sides at 10, 30, 60 and 90 degrees of flexion. Specific releases were identified and noted based on matrix profiling after each test. Re-iteration loops were enacted until balance within 15 lbs. of difference was achieved. The data was expressed as the ratio of medial/total force (total=medial + lateral), with 0.5 being equal lateral and medial forces. This was named the Contact Load Ratio (CLR). The load distribution was expressed as a scatter graph of lateral v. medial compartmental loads (Figure 1)


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_I | Pages 87 - 87
1 Mar 2005
Noriega F
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Introduction and purpose: Posttraumatic compartmental syndromes of the deep posterior compartment of the leg are usually given an incorrect diagnosis. There can be an involvement of the three muscles of the posterior compartment (albeit to different degrees) and muscle necrosis can cause a retraction that flexes the hallux and other toes as well as varus hindfoot and various degrees of equinus and cavus, hindering gait. We revised patients operated on who had had previous tibia and fibular fractures which had led to subsequent foot deformities.

Materials and methods: Seven patients were operated on in 5 years. The whole of the fibrous scar tissue was removed from the involved muscle and tendon and a medial capsule release was performed. A subtalar arthrodesis was carried out, laterally displacing the calcaneus under the talus, to correct the varus hindfoot. In addition a transplant of the FHL was made to the base of first phalanx as well as a transplant of the EHL to the base of the first metatarsal/tibialis anterior and a tenodesis of the distal end to EHB. The small toes were treated by means of a replacement of the extensor longus by the extensor brevis and an intrinsicoplasty of every toe.

Results: Using the AOFAS ankle and hindfoot scales, the mean postop score was e 90.8 points (range: 62–100), for hallux and small toes it was 90.2 points (range: 67–100). 5 patients (71.4 %) were considered to have obtained excellent results, 1 good and 1 poor. As regards complications, there was one instance of varus recurrence and one case of late consolidation.

Conclusions: Repair after a compartmental syndrome can be successfully carried out to achieve a plantigrade foot that allows ambulation.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 172 - 172
1 Mar 2006
Qureshi A McGee A Porter K
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The clinical diagnosis of an acute compartment syndrome is most reliably based on increasing pain and pain on stretching the affected muscle groups. These signs cannot be elicited in the presence of epidural or regional blocks, or if the patient is unconscious. We present a national audit of consultant trauma and orthopaedic surgeons on the use of compartmental pressure monitoring in such patients. The postal questionnaire also asked whether a departmental protocol was in use and whether regional and epidural blocks were withheld in patients at risk of developing an acute compartment syndrome.

17% of consultants had such an agreed protocol, 53% did not have access to a continuous pressure monitoring device, 58% would request for an epidural/regional block to be withheld with only 2% routinely measuring compartment pressures in the presence of such a block.

This study highlights a major deficiency in the clinical approach to a relatively common condition that may result in limb and life threatening complications and supports the recommendation for compartmental monitoring equipment to be made available.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIX | Pages 27 - 27
1 Jul 2012
White SP Forster MC Joshy S
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Background. Dual compartment knee replacement has been introduced to allow sparing of the cruciate ligaments and lateral compartment and preserve some biomechanics of knee function. Aim. To study the early clinical and radiographic results of this new prosthesis. Method. Patients who underwent dual compartmental knee arthroplasty performed by 2 surgeons over a period of one year were studied prospectively. All subjects in the study had advanced symptomatic osteoarthritis of the medial and patellofemoral joints but had an intact ACL and preserved lateral compartment. All patients received the Journey Deuce Dual Compartmental Knee System (Smith & Nephew, Inc, Memphis, Tenn) with Oxinium femoral component and modular tibial component. Follow-up with clinical evaluation, radiographs and Oxford knee scores were performed at 6 weeks, 6 months, 1 year, 2 years. Results. Mean follow up was 18months (range 12-24months). There were 15 patients (6 males, 9 females) with a mean age of 53 years (range, 46-68 years). Twelve of the 15 patients had their patella resurfaced. The mean inpatient stay was 4.5 days (range 3-11 days). The mean time taken for surgery was 80 minutes (range 77-112 minutes). Six of the 15 patients had poor results following surgery. Five out of six patients with poor results had tibial base plate loosening. This was confirmed either on plain x-rays, bone scan or at the time of revision surgery. Patients with tibial base plate loosening typically presented with persistent pain, particularly of the metaphyseal region when weightbearing and an effusion. One revision was performed for patellofemoral pain and maltracking. In total, three patients have already been revised and three are awaiting revision surgery. Further procedures were required in 2 patients. Conclusion. The Deuce dual compartmental knee replacement in its current design results in an unacceptably high rate of failure due to tibial base plate loosening. Some of these patients had good results in the early postoperative period which then deteriorated. Considering the high rates of failure we do not recommend this replacement with its current tibial plate design


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 223 - 223
1 May 2009
Mackenzie G Chess D Deshpande S Johnson J Kedgley A
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Optimal soft tissue tension maximises function following total knee arthroplasty. Excessive tension may lead to stiffness and or pain, while inadequate tension can lead to instability. Composite component thickness is a prime determinant of this soft tissue tension. The variable component thickness provided by polyethylene inserts generally allows for 2–3mm incremental change. This study analyzed the effect of 1-mm incremental changes in polyethylene thickness on soft tissue tension. Our hypothesis was that soft tissue tension would be markedly affected by increases in insert thickness. Computer assisted TKA was performed on eight cadaveric knee specimens (four pairs). The knees were passively moved through full flexion-extension range of motion, for each tibial construct thickness. Kinematics were recorded using the computer navigation software. Soft tissue tension was analyzed by measuring compartmental loads. A validated load cell instrumented tibial insert was used to measure medial and lateral compartmental loads independently. The effect of 1-mm increments in polyethylene thickness on compartmental loads was evaluated. An increase in compartmental loads was measured with increasing insert thickness. Loading in contralateral compartments showed differing behaviour, reflecting varying tension in the medial and lateral sides. Many generated loads showed a reduction after reaching a maximal level with further increase in insert thickness (seven of eight specimens), indicative of tissue failure, although there were no overt indications of failure during the procedure. With a 1-mm increase in insert thickness, six of eight specimens showed an increase in peak loads greater than 100N at some point in the testing procedure, although not always with the same shim thickness. Compartmental loads varied as a function of insert thickness. Most specimens showed signs of soft tissue “micro-failure”. The high sensitivity of compartmental loads to a 1-mm incremental increase is significant and has not been previously appreciated, especially intra-operatively. Currently available inserts with 2–3mm incremental sizes may make obtaining optimal soft tissue tension difficult. In addition to the current focus of obtaining accurate leg alignment, further computer-assisted techniques are required to address soft tissue tension


Aims

Functional alignment (FA) in total knee arthroplasty (TKA) aims to achieve balanced gaps by adjusting implant positioning while minimizing changes to constitutional joint line obliquity (JLO). Although FA uses kinematic alignment (KA) as a starting point, the final implant positions can vary significantly between these two approaches. This study used the Coronal Plane Alignment of the Knee (CPAK) classification to compare differences between KA and final FA positions.

Methods

A retrospective analysis compared pre-resection and post-implantation alignments in 2,116 robotic-assisted FA TKAs. The lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) were measured to determine the arithmetic hip-knee-ankle angle (aHKA = MPTA – LDFA), JLO (JLO = MPTA + LDFA), and CPAK type. The primary outcome was the proportion of knees that varied ≤ 2° for aHKA and ≤ 3° for JLO from their KA to FA positions, and direction and magnitude of those changes per CPAK phenotype. Secondary outcomes included proportion of knees that maintained their CPAK phenotype, and differences between sexes.


The Bone & Joint Journal
Vol. 104-B, Issue 5 | Pages 604 - 612
1 May 2022
MacDessi SJ Wood JA Diwan A Harris IA

Aims

Intraoperative pressure sensors allow surgeons to quantify soft-tissue balance during total knee arthroplasty (TKA). The aim of this study was to determine whether using sensors to achieve soft-tissue balance was more effective than manual balancing in improving outcomes in TKA.

Methods

A multicentre randomized trial compared the outcomes of sensor balancing (SB) with manual balancing (MB) in 250 patients (285 TKAs). The primary outcome measure was the mean difference in the four Knee injury and Osteoarthritis Outcome Score subscales (ΔKOOS4) in the two groups, comparing the preoperative and two-year scores. Secondary outcomes included intraoperative balance data, additional patient-reported outcome measures (PROMs), and functional measures.