Quadriceps Sparing Research Articles

GNE Myopathy: Genotype - Phenotype Correlation and Disease Progression in an Indian Cohort.

GNE myopathy is a rare slowly progressive adult-onset distal myopathy with autosomal recessive inheritance. It has distinctive features of quadriceps sparing with preferential anterior tibial involvement. Most patients eventually become wheelchair bound by 10-20 years after onset. This study analyzes the phenotype-genotype characteristics and disease progression in a large cohort of GNEM patients from India. Retrospective observational study on GNEM from a quaternary neurology referral hospital in southern India. Data was collected from clinical phenotyping, serum creatine kinase levels, muscle biopsy histopathology, genetic analysis and functional assessment scales - IBMFRS and MDFRS. 157 patients were included with mean age at onset and diagnosis: 26.5±6.2 years and 32.8±7.8 years, respectively. M:F ratio was 25 : 13. Most common presenting symptom: foot drop (46.5%) and limb girdle weakness (19.1%). Wasting and weakness of small muscles of hand and finger flexors seen in 66.2% and as an initial symptoms in 5.2%. Though tibialis anterior involvement was most common (89.2%), early quadriceps weakness was noted in 3.2% and Beevor's sign in 59.2%. Rimmed vacuoles were present in 75% of patients with muscle biopsy. Most common variant was the Indian Founder variant identified in 129 patients (c.2179 G>A, p.Val727Met - 82.2%) and most common zygosity being compound heterozygous state (n = 115, 87.5%). Biallelic kinase domain variations predisposed to a more severe phenotype. Wheelchair bound state noted in 8.9% with a mean age and duration of 32.0±7.1 and 6.3±4.9 years respectively, earlier than previous studies on other ethnic groups. This is the largest GNEM cohort reported from South Asia. The p.Val727Met variant in compound heterozygous state is noted in majority (82.2%) of the cases. Observed relationships between genotype and clinical parameters shows that severity of the disease might be attributable to specific GNE genotype and thus could aid in predicting the disease progression.

Current Concepts in Management of Distal Femur Fractures

Recent studies report the overall incidence of distal femur fractures as 8.7/100,000/year. This incidence is expected to rise with high energy motor vehicle collisions and elderly osteoporotic fractures in native and prosthetic knees keep increasing. These fractures are more common in males in the younger age spectrum while females predominate for elderly osteoporotic fractures. Surgical treatment is recommended for these fractures to maintain articular congruity, enable early joint motion and assisted ambulation. Over the last two decades, development of minimally invasive and quadriceps sparing surgical approaches, availability of angle stable implants have helped achieve predictable healing and early return to function in these patients. Currently, laterally positioned locked plate is the implant of choice across all fracture patterns. Retrograde with capital implantation of intramedullary nails with provision for multiplanar distal locking is preferred for extra-articular and partial articular fractures. Even with these advancements, nonunion after distal femur fracture fixation can be as high as 19%. Further recent research has helped us understand the biomechanical limitations and healing problems with lateral locked plate fixation and intramedullary nails. This has lead to development of more robust constructs such as nail-plate and double plate constructs aiming for improved construct strength and to minimise failures. Early results with these combination constructs have shown promise in high risk situations such as fractures with extensive metaphyseal fragmentation, osteoporosis and periprosthetic fractures. These constructs however, run the risk of being over stiff and can inhibit healing if not kept balanced. The ideal stiffness that is needed for fracture healing is not clearly known and current research in this domain has lead to the development of smart implants which are expected to evolve and may help improve clinical results in future.

Lateral Subvastus Lateralis versus Medial Parapatellar Approach for Total Knee Arthroplasty: Patient Outcomes and Kinematics Analysis.

The conventional approach for total knee arthroplasty (TKA) is a medial parapatellar approach (MPA). We aimed to study patient outcomes and kinematics with a quadriceps sparing lateral subvastus lateralis approach (SLA). Patients with neutral/varus alignment undergoing primary TKA were consented to undergo the SLA. At 1-year postoperative, patients underwent radiostereometric analysis. Patients were administered the Short Form 12 (SF-12), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Knee Society Score (KSS). Kinematics and outcome data were compared to a group undergoing TKA via conventional MPA. Fourteen patients underwent TKA via SLA with a mean age 71.5 ± 8.0 and mean body mass index (BMI) 31.0 ± 4.5. The MPA group had 13 patients with mean age 63.4 ± 5.5 (p = 0.006) and mean BMI 31.2 ± 4.6 (p = 0.95). The SLA resulted in a significantly more posterior medial contact point at 0 (p = 0.011), 20 (p = 0.020), and 40 (p = 0.039) degrees of flexion. There was no significant difference in medial contact point from 60 to 120 degrees, lateral contact point at any degree of flexion, or axial rotation. There was no difference in improvement in postoperative WOMAC, SF-12, KSS function, and total KSS knee scores between groups. The MPA group had a significantly greater improvement in KSS knee scores at 3 months (p < 0.001), 1 year (p = 0.003), and 2 years (p = 0.017). The SLA resulted in increased medial femoral rollback early in flexion. Although both approaches resulted in improved postoperative outcomes, the MPA group showed significantly greater improvements in KSS knee scores at 3 months, 1 year, and 2 years. Further studies are required to identify any benefits that the SLA may offer. LEVEL OF EVIDENCE: Therapeutic Level II.

Case of anti‐NT5c1A antibody‐seropositive inclusion body myositis associated with severe dysphagia and prominent forearm weakness

AbstractWe report a case of an 82‐year‐old woman with inclusion body myositis (IBM), who presented with severe dysphagia, finger flexor weakness, and respiratory dysfunction. In addition, the patient showed prominent forearm weakness with quadriceps sparing and was seropositive for the anti‐cytosolic 5′‐nucleotidase 1A (NT5c1A) antibody. The presence of the anti‐NT5c1A antibody is presumably associated with dysphagia. We speculate that the anti‐NT5c1A antibody is associated with the large discrepancy between distal upper limb weakness and proximal lower limb weakness in IBM.

Swashbuckler approach for distal femur fractures: A systematic review

PurposeThe review aims to reach a common consensus regarding the swashbuckler approach for distal femur fractures by a systematic review of the available literature and to evaluate the complications, union, and outcomes. MethodsElectronic database search engines like Cochrane Library, PubMed, Google Scholar, and Scopus were searched until May 2021. Studies comparing the clinical complications, and functional outcome scores of Swashbuckler approach for distal femur were considered. The quality of the articles were evaluated using Methodological Index for Non-Randomized Studies score. ResultsEleven studies were included for the final analysis. An anterior midline incision was used in the majority of studies. Superficial infection was the most common complication seen followed by knee stiffness and deep infections. 66.45% of the patients had excellent/good outcomes. 1.08% had a painful implant and 1.89% had deep infection. ConclusionSwashbuckler approach offers itself as a viable option in cases of distal femur fractures, especially in AO type C. The quadriceps sparing approach provides excellent/good outcomes in approximately 66.45% of the patients.

Comparison of minimally invasive approaches and standard median parapatellar approach for total knee arthroplasty: A systematic review and network meta-analysis of randomized controlled trials.

Minimally invasive total knee arthroplasty (TKA) has been actively advertised by the orthopedic industry. The purpose of this network meta-analysis was to comprehensively compare the effectiveness of four minimally invasive surgery (MIS) approaches and the medial parapatellar (MPP) approach to improve the American Knee Society Score (KSS) in primary TKA. Studies were comprehensively searched on PubMed, Embase, Cochrane Library (CENTRAL), Web of Science and Science Direct up to June 2018 with a major focus on the outcome of KSS. Risk of bias was assessed using the Cochrane risk of bias tool. Quality assessment was performed using the GRADE system. Both pair-wise and network meta-analyses are calculated to comprehensively compare the effectiveness of four MIS and TKA approaches. Eleven trials with 1025 knees undergoing TKA were included. Our analysis showed that both MPP and MIS approaches provided improvement in terms of short-term (four-eight weeks) total, objective and functional KSS. The network-meta analysis revealed that MIS approaches showed a trend towards superior KSS improvement over standard MPP approaches. However, statistical advantages were only observed in the mini-MPP group for functional KSS compared to the conventional MPP and quadriceps-sparing (QS) groups. Evidence shows that MIS TKA approaches are effective alternatives to MPP approaches. However, orthopedic surgeons should be cautiously optimistic about minimally invasive TKA in terms of KSS improvement.

Quadriceps-sparing versus traditional medial parapatellar approaches for total knee arthroplasty: a meta-analysis

BackgroundThere is still controversy regarding whether Quadriceps-sparing (QS) approach for total knee arthroplasty (TKA) lead to better earlier recovery as well as compromising low limb alignment and prosthesis position compared with conventional medial parapatellar (MP) approach. To overcome the shortcomings and inaccuracies of single studies, the clinical outcomes and radiographic assessments of QS approach and MP approach were evaluated through meta-analysis.MethodsWe performed this meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. A literature search was conducted in the PubMed, EMBase, Cochrane Collaboration Library and Web of Science databases. Our search strategy followed the requirements of the Cochrane Library Handbook. The study selection, data extraction and assessment of methodological quality were independently completed by four authors. And subgroup analysis and publication bias were also performed in the study.ResultsEight prospective randomized controlled trials (RCTs) and eight retrospective studies were identified. Overall meta-analysis and subgroup meta-analysis of RCTs identified the QS approach mainly was associated with increased Knee Society function score beyond 24 months postoperatively (weighted mean difference [WMD] 1.78, P = 0.0004) (WMD 1.86, P = 0.0002), and improved range of motion 1–2 weeks postoperatively (WMD 5.84, P < 0.00001) (WMD 4.87, P = 0.002). Besides, lower visual analogue scale on postoperative day 1 (WMD -0.91, P = 0.02), shorter hospital stay (WMD -0.88, P = 0.02) and shorter incision (extension) (WMD -4.62, P < 0.00001) were indicated in overall meta-analysis. However, surgical and tourniquet time was significantly longer in QS group by both overall and subgroup meta-analysis.ConclusionsQS approach may accelerate early recovery without increasing the risk of malalignment of low limb and malposition of prosthesis.

Distal myopathy with rimmed vacuoles: Spectrum of GNE gene mutations in seven Chinese patients

Distal myopathy with rimmed vacuoles (DMRV) is a rare, autosomal, recessive inherited disease caused by mutations in the GNE gene. DMRV is an adult-onset disorder characterized by progressive muscle atrophy and weakness, which initially involves the distal muscles with quadriceps sparing. To date, >150 GNE mutations have been reported in different populations from around the world. The present study investigated the clinical, pathological and genetic characteristics of seven unrelated DMRV patients from China. Genetic analysis in these patients revealed three novel mutations (c.455_456insC, p.P421L, and p.A287T) and five previously reported mutations (p.D207V, p.C44S, p.G576R, p.A669P, and p.D218G). In addition, the literature on DMRV was reviewed to provide an overview of the disease and broaden the mutational spectrum of the GNE gene in China.

Substantial deficiency of free sialic acid in muscles of patients with GNE myopathy and in a mouse model.

GNE myopathy (GNEM), also known as hereditary inclusion body myopathy (HIBM), is a late- onset, progressive myopathy caused by mutations in the GNE gene encoding the enzyme responsible for the first regulated step in the biosynthesis of sialic acid (SA). The disease is characterized by distal muscle weakness in both the lower and upper extremities, with the quadriceps muscle relatively spared until the late stages of disease. To explore the role of SA synthesis in the disease, we conducted a comprehensive and systematic analysis of both free and total SA levels in a large cohort of GNEM patients and a mouse model. A sensitive LC/MS/MS assay was developed to quantify SA in serum and muscle homogenates. Mean serum free SA level was 0.166 μg/mL in patients and 18% lower (p<0.001) than that of age-matched control samples (0.203 μg/mL). In biopsies obtained from patients, mean free SA levels of different muscles ranged from 0.046–0.075 μg/μmol Cr and were markedly lower by 72–85% (p<0.001) than free SA from normal controls. Free SA was shown to constitute a small fraction (3–7%) of the total SA pool in muscle tissue. Differences in mean total SA levels in muscle from patients compared with normal controls were less distinct and more variable between different muscles, suggesting a small subset of sialylation targets could be responsible for the pathogenesis of GNEM. Normal quadriceps had significantly lower levels of free SA (reduced by 39%) and total SA (reduced by 53%) compared to normal gastrocnemius. A lower SA requirement for quadriceps may be linked to the reported quadriceps sparing in GNEM. Analysis of SA levels in GneM743T/M743T mutant mice corroborated the human study results. These results show that serum and muscle free SA is severely reduced in GNEM, which is consistent with the biochemical defect in SA synthesis associated with GNE mutations. These results therefore support the approach of reversing SA depletion as a potential treatment for GNEM patients.

Quadriceps sparing (subvastus/midvastus) approach versus the conventional medial parapatellar approach in primary knee arthroplasty

IntroductionQuadriceps-sparing (subvastus/midvastus) approach has emerged as an alternative to the classical medial parapatellar approach in total knee arthroplasty with the results claiming faster rehabilitation in the quadriceps sparing group. The present study was conducted to determine if the quadriceps sparing (subvastus/midvastus) approach offers any advantages over the classical medial parapatellar approach in primary knee replacements. Material and methods55 patients undergoing unilateral TKA were randomized into two groups: the subvastus/midvastus group and the medial parapatellar group. The patients were assessed preoperatively and postoperatively at 7 days, 1 month, 3 months and finally at 6 months. Knee Society Scoring was used to compare the groups. Perioperative blood loss, duration of surgery and need for lateral release were also compared. The patient was kept on same pain management and postoperative rehabilitation protocol. Statistical analyses tested the null hypotheses of no differences in patients treated with either group at 95% significance level (p<0.05). ResultsThe difference between the two groups in terms of duration of surgery and perioperative blood loss were statistically not significant. Lateral release was required in 13.8% of patients in the parapatellar group compared to 3.8% of patients in the quadriceps-sparing group. On comparing the postoperative Knee Society Scores of the two groups at each follow up the difference was statistically significant at 7 days and 4 weeks postoperatively (p value<0.05) but the difference between the two groups at 3 and 6 months was not significant statistically (p value>0.05). ConclusionQuadriceps sparing approach (subvastus/midvastus) offers advantages over the standard medial parapatellar approach in terms of better pain relief and faster rehabilitation in the early postoperative period.

Distal Femur AO type 33 B – Surgical options, Results and Complications (including Hoffa’s fracture)

Background: Distal femur AO type 33 B fractures are partial articular fractures. It also includes Hoffa’s fracture which is a relatively rare injury and requires always operative management even with no displacement. Approach to these fracture depend on the condyle involved also various quadriceps sparing approach like swashbuckler approach has been described in the literature. Surgical treatment of these fractures involves anatomical reduction, compression, stable fixation and early mobilization. Treatment modalities such as cancellous screws, pre-contoured anatomical locked plate, posterior condylar buttress plating, distal retrograde interlocking nailing, angled blade plate fixation, dynamic condylar screw may be considered. Each implant is associated with advantages and disadvantages which is discussed here.

GNE myopathy

GNE myopathy is a rare neuromuscular disease whose description is fairly recent. It predominantly affects the adult population and is an inherited autosomal recessive disorder. Although universal and ubiquitous, GNE myopathy prevails in the Jewish community of Persian origin, living in Iran, Israel or in the United States. This condition has also been reported in great number in populations of far-East Asia (Japan and neighboring countries) and, closer to France, in Bulgaria. GNE myopathy causes muscle weakness in the extremities (distal myopathy), affecting initially and predominantly foot flexor muscles. The generic term of GNE myopathy is now fully accepted and encompasses two previously described entities: the quadriceps sparing myopathy, (also referred to as the autosomal recessive form of inclusion body myopathy (hIBM) and the Nonaka type distal myopathy (or distal myopathy with rimmed vacuoles DMRV). This myopathy is due to mutations in the GNE gene encoding a bifunctional enzyme, the UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine kinase. This enzyme plays a role at two levels in the metabolic pathway leading to the synthesis of sialic acid. Sialic acid, also known as N-acetylneuraminic acid (Neu5Ac or NANA), is a monosaccharide essential to other protein or lipid molecules requiring sugar residues on their surface in order to function efficiently. GNE myopathy is characterized by histological lesions (rimmed vacuoles) within muscle fibers. They are fairly typical in a suggestive context, but non-specific and inconsistent from one muscle to another. The diagnosis of GNE myopathy is essentially based on clinical clues, including muscle imaging, and is confirmed by genetic studies. If promising therapeutic trials are being developed to compensate for this recently unveiled metabolic defect, the treatment of this myopathy remains purely supportive to date.

GNE Myopathy: Two Clusters with History and Several Founder Mutations.

GNE myopathy (previous names: HIBM, DMRV, IBM2) is a unique distal myopathy with quadriceps sparing. This recessively inherited myopathy has been diagnosed in various regions of the world with more than 150 disease-causing mutations already identified. Several of those are proven or suspected to be founder mutations in certain regional clusters and are described in this review. The review also discusses some historical aspects that might be relevant to the mutational distribution.

English

Background: The most common approaches used in Total Knee Replacement surgery are Midvastus, subvastus, median parapetellar, lateral patellar and trivector approach. There is uncertainty as to the best surgical approach to the knee joint for knee replacement. Median parapetellar approach is the standard of practice, but off late quadriceps sparing approaches as like subvastus and midvastus are performed. Subvastus approach has its own limitation of less joint exposure. In our clinical setup, orthopaedic surgeons perform median parapetellar and midvastus approach. The present study has compared outcome of knee function between a standard median parapetellar arthrotomy and mid vastus arthrotomy for patients undergone primary total knee arthroplasty. The post op quadriceps function depend on the type of surgical approach Materials and methods: 30 subjects were recruited who had undergone Total knee arthroplasty with Median parapetellar and Midvastus approach at Sri Ramachandra medical hospital; received standard physiotherapy care. The pre-op and post quadriceps angle were measured and the quadriceps, hamstrings isometric muscle strength and 6 minute walk test of the patients were recorded at the time of discharge and after one month of follow-up, and the data were statistically analyzed. Results: Median parapetellar and Midvastus approach were significant within the groups; with respect to quadriceps angle (QA) (p<0.05), isometric strength of quadriceps (QS) (p<0.05) and 6 minute walk test (WT) (p<0.05). On comparing between the groups at one month follow-up isometric strength of hamstrings (HS) (p<0.01) and 6 minute walk test (p<0.01) were found to be significant. Discussion: Findings show that Mid-vastus approach provides better results in terms of quadriceps angle, isometric strength of quadriceps and 6 minute walk test compared to median parapetellar approach. Conclusion: Study concludes that, the isometric strength of quadriceps and hamstrings has improved at the time of discharge and after one month of follow up (within the group). However no much significant changes seen between the groups.

Minimally invasive knee arthroplasty: An overview.

Minimally invasive surgery (MIS) for arthroplasty of the knee began with surgery for unicondylar knee arthroplasty (UKA). Partial knee replacements were designed in the 1970s and were amenable to a more limited exposure. In the 1990s Repicci popularized the MIS for UKA. Surgeons began to apply his concepts to total knee arthroplasty. Four MIS surgical techniques were developed: quadriceps sparing, mini-mid vastus, mini-subvastus, and mini-medial parapatellar. The quadriceps sparing technique is the most limited one and is also the most difficult. However, it is the least invasive and allows rapid recovery. The mini-midvastus is the most common technique because it affords slightly better exposure and can be extended. The mini-subvastus technique entirely avoids incising the quadriceps extensor mechanism but is time consuming and difficult in the obese and in the muscular male patient. The mini-parapatellar technique is most familiar to surgeons and represents a good starting point for surgeons who are learning the techniques. The surgeries are easier with smaller instruments but can be performed with standard ones. The techniques are accurate and do lead to a more rapid recovery, with less pain, less blood loss, and greater motion if they are appropriately performed.

Early Patient Outcomes After Primary Total Knee Arthroplasty with Quadriceps-Sparing Subvastus and Medial Parapatellar Techniques: A Randomized, Double-Blind Clinical Trial.

Techniques that reduce injury to the knee extensor mechanism may cause less pain and allow faster recovery of knee function after primary total knee arthroplasty. A quadriceps-sparing (QS) subvastus technique of total knee arthroplasty was compared with medial parapatellar arthrotomy (MPPA) to determine which surgical technique led to better patient-reported function and less postoperative pain and opioid utilization. In this prospective, double-blind study, 129 patients undergoing total knee arthroplasty were randomized to the QS or the MPPA group after skin incision. All surgical procedures utilized minimally invasive surgery principles and standardized anesthesia, implants, analgesia, and rehabilitation. The Knee Society Score (KSS) was obtained at baseline and one and three months after surgery. Weekly telephone interviews were used to collect patient-reported outcomes including ambulatory device use, the UCLA (University of California Los Angeles) activity score, performance of daily living activities, and opioid utilization. No differences between groups were seen in opioid utilization, either during the acute hospitalization or in the eight weeks after surgery. The QS group reported significantly less pain at rest on postoperative day one and with activity on day three (p = 0.04 for each). Compared with baseline, both groups showed significant improvements in the KSS at one month (MPPA, p = 0.0278; QS, p = 0.0021) and three months (p < 0.0001 for each) as well as week-to-week gains in walking independence through five weeks after surgery. Independence from ambulatory devices outside the home lagged behind independence indoors by about two weeks in both groups. When primary total knee arthroplasty was performed with contemporary minimally invasive surgery principles and standardized implants, anesthesia, and postoperative pathways, the QS technique yielded no significant early functional advantages or differences in opioid utilization compared with the MPPA technique. However, the mean pain scores reported by patients in the QS group were slightly lower at rest on postoperative day one and during activity on day three. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Two recurrent mutations are associated with GNE myopathy in the North of Britain

ObjectiveGNE myopathy is a rare recessive myopathy associated with inclusion bodies on muscle biopsy. The clinical phenotype is associated with distal muscle weakness with quadriceps sparing. Most of the current...

GNE myopathy: New name and new mutation nomenclature

The recessively inherited, adult onset, quadriceps sparing myopathy with a predilection for distal muscles has received multiple historic names. The disorder was described in 1981 in Japanese patients and termed Nonaka Distal Myopathy [1], later commonly referred to as Distal Myopathy with Rimmed Vacuoles (DMRV) (OMIM#605820). In 1984, the disorder was described as vacuolar myopathy sparing the quadriceps in Iranian-Jewish patients [2], later commonly referred to as Inclusion Body Myopathy 2 (IBM2) or Hereditary Inclusion Body Myopathy (HIBM) (OMIM#600737).

Minimally invasive total knee arthroplasty; a pragmatic randomised controlled trial reporting outcomes up to 2 year follow up

BackgroundWe present a prospective, randomised, multi-surgeon, controlled trial comparing minimally invasive (MIS) and standard approach total knee arthroplasty (TKA). MethodsParticipants underwent unilateral TKA. Patients were randomised to Bristol, quadriceps sparing MIS or standard medial parapatellar approaches. Length of stay with secondary outcome measures including knee range of movement, Oxford Knee Score (OKS), Western Ontario and McMaster Universities Arthritis Index (WOMAC) and American Knee Society Score (KSS) up to 2years. Radiographic and post operative assessment was blinded. Results86 patients (92 knees) participated in the study. Mean operative time between MIS and control groups was 95.5 (95% CI 90.0–101.0) and 94.8 (95% CI 88.2–101.4) minutes respectively. Mean readiness for discharge was shorter in the MIS group 4.5±1.5 (95% CI, 4.1–4.9) days versus 5.9±2.7 (95% CI, 5.1–6.7) days amongst controls (p=0.004). Patients in the MIS group had fewer complications (p=0.003). One patient developed a deep vein thrombosis (DVT) and one required revision surgery, both in the control group.83 patients completed follow up to 2years (40 MIS, 43 controls). Range of movement and other outcome measures improved up to 1year post-operatively with no statistically significant differences between MIS and controls. We found no evidence of radiographic loosening in either group at the 2year follow up. ConclusionsMIS offers reduced length of stay and fewer complications for patients following TKR without evidence of component mal-alignment. Our findings of fewer systemic complications in MIS TKR patients warrant further future study. Level of evidenceLevel 1

Comparison of the clinical and radiological outcomes of three minimally invasive techniques for total knee replacement at two years

Minimally invasive total knee replacement (MIS-TKR) has been reported to have better early recovery than conventional TKR. Quadriceps-sparing (QS) TKR is the least invasive MIS procedure, but it is technically demanding with higher reported rates of complications and outliers. This study was designed to compare the early clinical and radiological outcomes of TKR performed by an experienced surgeon using the QS approach with or without navigational assistance (NA), or using a mini-medial parapatellar (MP) approach. In all, 100 patients completed a minimum two-year follow-up: 30 in the NA-QS group, 35 in the QS group, and 35 in the MP group. There were no significant differences in clinical outcome in terms of ability to perform a straight-leg raise at 24 hours (p = 0.700), knee score (p = 0.952), functional score (p = 0.229) and range of movement (p = 0.732) among the groups. The number of outliers for all three radiological parameters of mechanical axis, frontal femoral component alignment and frontal tibial component alignment was significantly lower in the NA-QS group than in the QS group (p = 0.008), but no outlier was found in the MP group. In conclusion, even after the surgeon completed a substantial number of cases before the commencement of this study, the supplementary intra-operative use of computer-assisted navigation with QS-TKR still gave inferior radiological results and longer operating time, with a similar outcome at two years when compared with a MP approach.