A modified oblique incision in hamstring tendon graft harvesting during ACL reconstruction.

BACKGROUND: During anterior cruciate ligament (ACL) reconstruction, different methods of harvesting hamstring tendon may lead to different degrees of injury to the inferior patellar branch of the saphenous nerve (IPBSN). Most of recent studies in the literature suggest that the classic oblique incision (COI) can reduce the incidence of IPBSN injury. We proposed a modified oblique incision (MOI) and compared it with the COI in terms of the resulting levels of injury and sensory loss and the clinical outcome. METHODS: Patients with ACL injury admitted to our hospital from April 2015 to July 2019 were randomly selected and included in our study. Thirty patients underwent the COI to harvest hamstring tendons, and the other 32 patients underwent the MOI. The pin prick test was performed to detect the sensation loss at 2 weeks, 6 months, and 1 year after the operation. Digital photos of the region of hypoesthesia area were taken, and then, a computer software (Adobe Photoshop CS6, 13.0.1) was used to calculate the area of the hypoesthesia. The length of the incision and knee joint functional score were also recorded. RESULTS: At the final follow-up, the incidence of IPBSN injury in COI and MOI were 33.3% and 9.4%, and the areas of paresthesia were 26.4±2.4 cm2 and 9.8±3.4 cm2 respectively. There was no significant difference in the incision length or knee functional score between the two groups. CONCLUSION: The MOI can significantly reduce the risk of injury to the IPBSN, reduce the area of hypoesthesia, and lead to high subjective satisfaction. Therefore, compared with the COI, the MOI is a better method of harvesting hamstring tendons in ACL reconstruction.

Patellar Denervation with Electrocautery Reduces Anterior Knee Pain within 1 Year after Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials.

OBJECTIVE: The effect of patellar denervation with electrocautery (PD) on anterior knee pain (AKP) after total knee arthroplasty (TKA) is still debated. The aim of this meta-analysis was to evaluate the current evidence regarding the use of PD in TKA without patellar resurfacing. METHODS: A computerized search of published studies was performed in the PubMed, Embase and Cochrane Library databases in December 2019. Eligible studies were randomized controlled trials (RCTs) comparing clinical outcomes of the PD group and the non-PD group. Subgroup analyses were carried out according to the follow-up time (3, 12 months, and over 12 months) to evaluate whether the clinical effect of PD changed with time. RESULTS: Ten RCTs were included in this meta-analysis. Pooled results showed a lower rate of AKP (Risk Ratio [RR] = 0.70; 95% confidence interval [CI], 0.50 to 0.97; P = 0.03) and a reduction in visual analogue scale (VAS) for AKP (mean difference, -0.37; 95% CI, -0.69 to -0.05; P = 0.02) in the PD group when compared to the non-PD group. Subgroup analyses found the differences in AKP incidence and VAS for AKP were significant at 3- and 12-month follow-up but not after 12-month follow-up. No significant difference was observed in functional scores between the two groups. No specific complication directly or indirectly related to PD was found. CONCLUSION: PD can decrease the incidence and severity of AKP within 12 months after TKA, but the effect cannot be maintained after 12-month follow-up. Without significant associated complication and reoperation, the use of PD is still recommended in TKA without patellar resurfacing.

Effect of Patellar Denervation on Anterior Knee Pain and Knee Function in Total Knee Arthroplasty without Patellar Resurfacing: A Meta-Analysis of Randomized Controlled Trials.

OBJECTIVE: The aim of the present study was to evaluate the effect of patellar denervation (PD) in preventing anterior knee pain (AKP) and improving knee function after total knee arthroplasty (TKA) without patellar resurfacing, and to help surgeons decide whether or not to use PD in TKA. METHODS: The electronic databases of Pubmed, Embase, Cochrane, Web of Science, and Scopus were searched for all randomized controlled trials (RCT) comparing the outcomes of PD and no patellar denervation (NPD) in TKA without patellar resurfacing. Primary outcomes were incidence of AKP, visual analogue scale for pain (VAS), and patellar score (PS). Secondary outcomes were Knee Society Score (KSS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Oxford Knee Score (OKS), knee range of motion (ROM), and complications. RESULTS: A total of nine RCT met the inclusion criteria. On meta-analysis, PD significantly reduced the incidence of AKP (odds ratio 0.49; 95% confidence interval [CI] 0.26 to 0.92), reduced the VAS (weighted mean difference [WMD] -0.57; 95% CI -1.02 to -0.11), and improved the WOMAC (WMD -4.63; 95% CI -6.49 to -2.77) and the ROM (WMD 9.60; 95% CI 0.39 to 18.81) during the follow-up within 12 months. In addition, PD improved the PS (WMD 1.01; 95% CI 0.65 to 1.38), KSS (WMD 1.12; 95% CI 0.10 to 2.14), and the WOMAC (WMD -1.41; 95% CI -2.74 to -0.08) during the follow-up after 12 months. CONCLUSION: Patellar denervation could significantly reduce the VAS and the incidence of AKP in the early stages after TKA as well as improve the clinical outcomes in terms of the PS, the WOMAC, the KSS, and the ROM. This study demonstrates that PD is a safe and recommendable technique that could be routinely performed in TKA.

Saphenous nerve injury after anterior cruciate ligament reconstruction: Reduced numbness area after ligamentoplasty using quadriceps tendon compared with hamstring tendon.

PURPOSE: Injury to the infra-patellar branches of the saphenous nerve (IPBSN) is the main neurological complication of anterior cruciate ligament (ACL) reconstruction procedures. Surgical technique using quadriceps tendon (QT) autograft allows a less invasive tibial approach potentially protecting the IPBSN. The aim of this study was to compare the numbness surface of the cutaneous area supplied by the IPBSN after ACL reconstruction using either hamstring tendon (HT) or QT autografts. METHODS: This was a retrospective comparative cohort study including 51 patients who underwent ACL reconstruction (27 QT and 24 HT) between January 2017 and April 2018. A sensory clinical evaluation was performed on each patient: length of the tibial scar, eventual numbness surface area and the type of sensory disorder were reported. To be considered as an IPBSN lesion, the numbness area had to spread at least one-centimeter away from the scar. RESULTS: The average follow-up was 15 months. In the HT group, the numbness area surface measured 21.2 ± 19 cm2 (0-77) and the scar length was on average 31.3 ± 5.6 mm. In the QT group, the numbness area was reduced to 5 ± 10 cm2 (P = .0007) as well as the scar length (13.3 ± 2.8 mm, P < .0001). We counted five (17.8%) and 19 (76%) real IPBSN lesions in the QT and HT groups, respectively (P = .0002). Hypoesthesia was the main sensory disorder observed (87.5%). CONCLUSION: Numbness area of the cutaneous surface supplied by the IPBSN after ACL reconstruction is reduced using QT autograft compared with HT autograft.

The efficacy of patellar denervation with electrocautery after total knee replacement: A meta-analysis of randomized controlled trials.

OBJECTIVE: To evaluate the efficacy and safety of patellar denervation with electrocautery for reducing pain and improving clinical outcomes after total knee replacement. METHODS: A comprehensive search was conducted across relevant databases, including PubMed, Scopus, EMBASE, Web of Science, and Cochrane Library databases on February 2020. Two researchers independently completed the literature screening, data extraction, and risk evaluation of bias. Outcome measures included visual analogue scale, opioid consumption, range of motion, patellar score, American Knee Society score, Oxford knee score and postoperative complications. STATA 13.0 software was applied for meta-analysis. RESULT: A total of nine studies involving 1319 patients were included in our study. The present meta-analysis indicated that patellar denervation with electrocautery was associated with improved pain relief and decreased opioid consumption after total knee replacement. There was significant difference between groups in terms of knee range of motion. CONCLUSION: Patellar denervation with electrocautery is effective in reducing pain and opioid consumption after total knee replacement. Postoperative range of motion is significantly better in patellar denervation group, which means that patellar denervation significantly improves clinical outcome.

Does Circumferential Patellar Denervation Result in Decreased Knee Pain and Improved Patient-reported Outcomes in Patients Undergoing Nonresurfaced, Simultaneous Bilateral TKA?

BACKGROUND: Anterior knee pain, which has a prevalence of 4% to 49% after TKA, may be a cause of patient dissatisfaction after TKA. To limit the occurrence of anterior knee pain, patellar denervation with electrocautery has been proposed. However, studies have disagreed as to the efficacy of this procedure.Questions/purposes We evaluated patients undergoing bilateral, simultaneous TKA procedures without patellar resurfacing to ask: (1) Does circumferential patellar cauterization decrease anterior knee pain (Kujala score) postoperatively compared with non-cauterization of the patella? (2) Does circumferential patellar cauterization result in better functional outcomes based on patient report (VAS score, Oxford knee score, and Knee Injury and Osteoarthritis Outcome Score) than non-cauterization of the patella? (3) Is there any difference in the complication rate (infection, patellar maltracking, fracture, venous thromboembolism, or reoperation rate) between cauterized patellae and non-cauterized patellae? METHODS: Seventy-eight patients (156 knees) were included in this prospective, quasi-randomized study, with each patient serving as his or her own control. Patellar cauterization was always performed on the right knee during simultaneous, bilateral TKA. Five patients (6%) were lost to follow-up before the 2-year minimum follow-up interval. A single surgeon performed all TKAs using the same type of implant, and osteophyte excision was performed in all patellae, which were left unresurfaced. Patellar cauterization was performed at 2 mm to 3 mm deep and approximately 5 mm circumferentially away from the patellar rim. The preoperative femorotibial angle and degree of osteoarthritis (according to the Kellgren-Lawrence grading system) were measured. Restoration of the patellofemoral joint was assessed using the anterior condylar ratio. Clinical outcomes, consisting of clinician-reported outcomes (ROM and Kujala score) and patient-reported outcomes (VAS pain score, Oxford knee score, and Knee Injury and Osteoarthritis Outcome Score), were evaluated preoperatively and at 1 month and 2 years postoperatively. Preoperatively, the radiologic severity of osteoarthritis, based on the Kellgren-Lawrence classification, was not different between the two groups, nor were the baseline pain and knee scores. The mean femorotibial angle of the two groups was also comparable: 189° ± 4.9° and 191° ± 6.3° preoperatively (p = 0.051) and 177° ± 2.9° and 178° ± 2.1° postoperatively (p = 0.751) for cauterized and non-cauterized knees, respectively. The preoperative (0.3 ± 0.06 versus 0.3 ± 0.07; p = 0.744) and postoperative (0.3 ± 0.06 versus 0.2 ± 0.07; p = 0.192) anterior condylar ratios were also not different between the cauterized and non-cauterized groups. RESULTS: At the 2-year follow-up interval, no difference was observed in the mean Kujala score (82 ± 2.9 and 83 ± 2.6 for cauterized and non-cauterized knees, respectively; mean difference 0.3; 95% confidence interval, -0.599 to 1.202; p = 0.509). The mean VAS pain score was 3 ± 0.9 in the cauterized knee and 3 ± 0.7 in the non-cauterized knee (p = 0.920). The mean ROM was 123° ± 10.8° in the cauterized knee and 123° ± 10.2° in the non-cauterized knee (p = 0.783). There was no difference between cauterized and non-cauterized patellae in the mean Knee Injury and Osteoarthritis Outcome Score for symptoms (86 ± 4.5 versus 86 ± 3.9; p = 0.884), pain (86 ± 3.8 versus 86 ± 3.6; p = 0.905), activities (83 ± 3.2 versus 83 ± 2.8; p = 0.967), sports (42 ± 11.3 versus 43 ± 11.4; p = 0.942), and quality of life (83 ± 4.9 versus 83 ± 4.7; p = 0.916), as well as in the Oxford knee score (40 ± 2.1 versus 41 ± 1.9; p = 0.771). Complications were uncommon and there were no differences between the groups (one deep venous thromboembolism in the cauterized group and two in the control group; odds ratio 0.49, 95% CI, 0.04-5.56; p = 0.57). CONCLUSIONS: Patellar cauterization results in no difference in anterior knee pain, functional outcomes, and complication rates compared with non-cauterization of the patella in patients who undergo non-resurfaced, simultaneous, bilateral, primary TKA with a minimum of 2 years of follow-up. We do not recommend circumferential patellar cauterization in non-resurfaced patellae in patients who undergo TKA. LEVEL OF EVIDENCE: Level II, therapeutic study.

Anatomical study of the infrapatellar branch of the saphenous nerve with applications to knee surgery / Estudio anatómico de la rama infrapatelar del nervio safeno con aplicaciones a la cirugía de rodilla

The infrapatellar branch of the saphenous nerve is a cutaneous nerve that innervates the area surrounding the patella and contributes to the peripatellar plexus. This nerve is target to iatrogenic injuries during a great deal of knee procedures, such as tendon harvesting, total knee arthroplasty and medial arthroscopic approaches to the knee. Lesion to this nerve can produce sensorial loss at its innervation territory. The study conducted herein aims to observe the anatomical aspects of the infrapatellar branch in cadaveric specimens. The infrapatellar branch of the saphenous nerve of 40 male cadavers was dissected with the purpose of identifying the number of branches, its relation with the patella, tibial tuberosity and sartorius muscle. The nerve was dissected and several measurements were performed with the aid of a digital caliper. Statistical analysis was performed with the MedCalc 16.1 software. The infrapatellar branch of the saphenous nerve was present in 100 % of the sample. Its mean distance from its origin to its branching point was 16.35±6.48 mm on the right and 21.94±4.31 mm on the left, with statistically significant differences (p < 0.05). A relatively safe zone for surgery was observed on the superior and medial aspect of the patella, which received less branches.

La rama infrapatelar del nervio safeno es un nervio cutáneo que inerva el área que rodea la patela y contribuye al plexo peripatelar. Este nervio es objeto de lesiones iatrogénicas durante una gran cantidad de procedimientos de rodilla, como la extracción de tendones, la artroplastía total de rodilla y los abordajes artroscópicos mediales de la rodilla. La lesión de este nervio puede producir pérdida sensorial en su territorio de inervación. El estudio realizado aquí tiene como objetivo observar los aspectos anatómicos de la rama infrapatelar en muestras de cadáveres. La rama infrapatelar del nervio safeno de 40 cadáveres masculinos se disecó con el propósito de identificar el número de ramas, su relación con la patela, la tuberosidad tibial y el músculo sartorio. Se disecó el nervio y se realizaron varias mediciones con la ayuda de un calibrador digital. El análisis estadístico se realizó con el software MedCalc 16.1. La rama infrapatelar del nervio safeno estaba presente en el 100 % de las muestras. La distancia media desde su origen hasta su punto de ramificación fue de 16,35±6,48 mm a la derecha y de 21,94±4,31 mm a la izquierda, con diferencias estadísticamente significativas (p <0,05). Se identificó una zona relativamente segura para la cirugía en el aspecto superior y medial de la patela, que recibió menos ramas.

Patellar Tendon Reflex and Vastus Medialis Hoffmann Reflex Are Down Regulated and Correlated in Women With Patellofemoral Pain.

OBJECTIVES: The aims of this study were threefold: (1) to compare the amplitude of patellar tendon reflex (T-reflex) between women with patellofemoral pain (PFP) and pain-free controls; (2) to compare the amplitude of vastus medialis Hoffmann reflex (VM H-reflex) between women with PFP and pain-free controls; (3) to investigate the association between the amplitude of patellar T-reflex and VM H-reflex in women with PFP and pain-free controls. DESIGN: Cross-sectional observational study. SETTING: Laboratory of biomechanics and motor control. PARTICIPANTS: Thirty women with PFP and 30 pain-free women aged 18 to 35 years (N=60). MAIN OUTCOME MEASURES: Peak-to-peak amplitudes of maximal VM H-reflex (elicited via electrical stimulation on the femoral nerve) and patellar T-reflex (elicited via mechanical percussion on the patellar tendon) were estimated. RESULTS: Women with PFP had significant lower amplitude of patellar T-reflex (mean difference=0.086; 95% confidence interval=0.020 to 0.151; P=.010; moderate effect) and VM H-reflex (mean difference=0.150; 95% confidence interval =0.073 to 0.227; P<.001; large effect) compared to pain-free controls. The VM H-reflex was strongly correlated with patellar T-reflex in both PFP group (r=0.66; P<.001) and control group (r=0.72; P<.001). CONCLUSIONS: As the T-reflex is easier to perform than H-reflex assessments in a clinical setting, it represents a feasible option to assess the impaired excitability of the stretch reflex pathway associated with PFP.

Ultrasound Anatomic Demonstration of the Infrapatellar Nerve Branches.

PURPOSE: To (1) confirm the correct identification of the infrapatellar branches of the saphenous nerve (IPBSNs) by high-resolution ultrasound (HRUS) with ink marking and consecutive dissection in anatomic specimens; (2) evaluate the origin, course, and end-branch distribution in healthy volunteers; and (3) visualize the variable anatomic course of the IPBSN by HRUS. METHODS: HRUS with high-frequency probes (15-22 MHz) was used to locate the IPBSN in 14 fresh anatomic specimens at 4 different locations. The correct identification of the IPBSN was verified by ink marking and consecutive dissection. Moreover, the IPBSNs were located in both knees of 20 healthy volunteers (n = 40). Their courses were marked on the volunteers' skin in a flexed-knee position. Distances were measured from the IPBSN branch closest to the median of the patella base (D1), center (D2), and apex (D3) and in a 45° (D4) and 0° (D5) relation to the median patella apex. Standardized photographs of all knees were mapped on 1 typically shaped knee. RESULTS: Dissection confirmed the correct identification of the IPBSN in 86% to 100% of branches, depending on their location. Intraindividual differences for distance measurements were observed for D1 (P < .001) and D2 (P = .002). The coefficient of variation was highest for D5 (0.86) and lowest for D1 (0.14). Mapping of the nerve branches on a typical knee showed a highly variable course for the IPBSN. CONCLUSIONS: This study confirmed the reliable ability to visualize the IPBSN and its variations with HRUS in anatomic specimens and in healthy volunteers; such visualization may therefore enhance the diagnostic and therapeutic management of patients with anteromedial knee pain. CLINICAL RELEVANCE: Ultrasound successfully pinpoints the variable course of the IPBSN from the origin to the most distal point and, therefore, may enable the correct identification of (iatrogenic) nerve damage in every location.

Association between incision technique for hamstring tendon harvest in anterior cruciate ligament reconstruction and the risk of injury to the infra-patellar branch of the saphenous nerve: a meta-analysis.

PURPOSE: To determine how the incision technique for hamstring tendon (HT) harvest in anterior cruciate ligament (ACL) reconstruction affects the risk of injury to the IPBSN and clinical outcome. METHODS: A systematic literature search of the MEDLINE/Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL) and EBSCOhost electronic databases and clinicaltrials.gov for unpublished studies was performed to identify comparative studies investigating injury to the IPBSN after HT ACL reconstruction by comparing at least two different incision techniques. Data were extracted for the number of patients with evidence of any neurologic deficit corresponding to injury to the IPBSN, area of sensory deficit, the Lysholm score and patient satisfaction. The mean difference (MD) in study outcome between incision groups was assessed. The relative risk (RR) and the number needed to treat (NNT) were calculated. The Chi-square and Higgins' I2 tests were applied to test heterogeneity. Data were pooled using a Mantel-Haenszel random-effects model if the statistical heterogeneity was > 50% and a fixed-effects model if the statistical heterogeneity was < 50%. The risk of bias was evaluated according to the Cochrane Database questionnaire and the quality of evidence was graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines. RESULTS: A total of eight studies (three randomized controlled trials (RCTs) and five comparative studies) were included, of which six compared vertical and oblique incisions, one horizontal and vertical incisions, and one compared all three techniques. HT harvest was performed through a vertical incision in 329 patients, through an oblique incision in 195 patients and through a horizontal incision in 151 patients. Considering the meta-analysis of the RCTs, the performance of a vertical incision significantly increased the risk of causing IPBSN deficiency compared with both oblique and horizontal incision [RR 1.65 (CI 1.10-2.49, p = 0.02) and RR 2.45 (CI 1.73-3.47, p < 0.0001), respectively]. A significantly larger area of sensory deficit was found with vertical incisions compared with oblique ones, with an MD of 22.91 cm2 (95% CI 7.73-38.08; p = 0.04). No significant differences were found between the incision techniques in relation to patient-reported outcomes. The same trend was obtained after the performing a meta-analysis of all eight included studies. The quality of evidence in this meta-analysis was determined as "low" to "moderate", mostly due to inadequate methods of randomization and high heterogeneity among the included studies. CONCLUSION: The performance of a vertical incision to harvest HTs for ACL reconstruction significantly increased the risk of iatrogenic injury to the IPBSN compared with both oblique and horizontal incisions. LEVEL OF EVIDENCE: Level I-III, meta-analysis of comparative studies.

Different Factors Conduct Anterior Knee Pain Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: A systematic review and meta-analysis was performed to investigate the risks associated with anterior knee pain (AKP) following primary total knee arthroplasty (TKA). METHODS: A computerized search was performed of the following databases: MEDLINE, Embase, and Cochrane Central (published prior to July 2017). A total of 37 studies, which included 1641 cases of AKP and 168,090 TKAs, were included in the meta-analysis. RESULTS: A subgroup analysis revealed that compared with those without the following medical conditions, patients who had an infrapatellar fat pad excision and more than 12 months of follow-up (odds ratio [OR] 12.58, 95% confidence interval [CI] 3.245-48.781) were more likely to have AKP after TKA. Circumpatellar electrocautery (>12 months: OR 0.50, 95% CI 0.326-0.760; ≤12 months: OR 0.59, 95% CI 0.408-0.867) and patellar resurfacing (OR 0.25, 95% CI 0.131-0.485) may decrease the risk of AKP. Other factors, including the prosthesis bearing type (mobile bearing or fixed bearing) and the approach (midvastus compared with the medial parapatellar approach), were not significant risk factors for AKP. CONCLUSION: The use of strategies such as patellar denervation and patellar resurfacing in primary TKA is recommended because they are safe and result in good clinical outcomes in preventing AKP. Caution should be taken when using an infrapatellar fat pad excision, because there is an increased risk of AKP at long-term follow-up (>12 months). Future studies should investigate these different strategies to confirm the underlying mechanisms and help prevent the occurrence of AKP after TKA. The timing of AKP onset remains unclear and requires further research.

Cryoneurolysis to treat the pain and symptoms of knee osteoarthritis: a multicenter, randomized, double-blind, sham-controlled trial.

OBJECTIVE: Evaluate the efficacy and safety/tolerability of cryoneurolysis for reduction of pain and symptoms associated with knee osteoarthritis (OA). DESIGN: Randomized, double-blind, sham-controlled, multicenter trial with a 6-month follow-up in patients with mild-to-moderate knee OA. Patients were randomized 2:1 to cryoneurolysis targeting the infrapatellar branch of the saphenous nerve (IPBSN) or sham treatment. The primary endpoint was the change from baseline to Day 30 in the Western Ontario and McMaster Osteoarthritis Index (WOMAC) pain score adjusted by the baseline score and site. Secondary endpoints, including visual analogue scale (VAS) pain score and total WOMAC score, were tested in a pre-defined order. RESULTS: The intent-to-treat (ITT) population consisted of 180 patients (n = 121 active treatment, n = 59 sham treatment). Compared to the sham group, patients who received active treatment had a statistically significant greater change from baseline in the WOMAC pain subscale score at Day 30 (P = 0.0004), Day 60 (P = 0.0176), and Day 90 (P = 0.0061). Patients deemed WOMAC pain responders at Day 120 continued to experience a statistically significant treatment effect at Day 150. Most expected side effects were mild in severity and resolved within 30 days. The incidence of device- or procedure-related adverse events was similar in the two treatment groups with no occurrence of serious or unanticipated adverse device effects (ADE). CONCLUSIONS: Cryoneurolysis of the IPBSN resulted in statistically significant decreased knee pain and improved symptoms compared to sham treatment for up to 150 days, and appeared safe and well tolerated.

Patellar denervation for Anterior Knee Pain Management in Knee Arthroplasty / Denervação patelar para tratamento da dor anterior na artroplastia total do joelho

OBJECTIVE: To compare the effectiveness of patellar denervation versus non-patellar denervation in reducing anterior knee pain on a follow-up period of at least one year after total knee arthroplasty. METHOD: Data from 84 patients, who underwent total knee arthroplasty were analyzed. Participants were divided into 2 groups; group A: 42 patients who previously underwent total knee arthroplasty with patellar denervation; and group B: 42 patients who previously underwent total knee arthroplasty without patellar denervation. Results were evaluated using WOMAC and KSS questionnaires, and the VAS pain measurement. Knee ranges of motion were measured. Preoperative clinical conditions of both groups were similar. RESULTS: Postoperatively, the following results were observed. (a), the WOMAC scores for group A were significant better when compared to group B (27.95 ± 5.89 vs. 33,55 ± 6.23; (b) better results were also found in KSS scores for group A vs. group B (86.19 ± 7.10 vs. 83,07 ± 4.88); (c) the range of knee flexion was smaller than in group A vs. group B (119.0 ± 10.7 vs 125.5 ± 11.0 degrees); (d) there was no significant difference between the mean of range of knee extension between the two groups groups; (e) in terms pain referred by the patient, no difference was observed according to VAS pain. CONCLUSION: Patellar denervation does not show better effect in pain reduction compared with TKA with non-patellar denervation. However, it had a better beneficial effect on knee function score, as measured through the KSS and WOMAC questionnaires.

OBJETIVO: Comparar a eficácia de denervação patelar em relação à não-denervação patelar na redução da dor anterior do joelho em um período de acompanhamento de no mínimo um ano após a artroplastia total do joelho (ATJ). MÉTODO: Foram analisados dados de 84 pacientes, submetidos a ATJ e divididos em 2 grupos: grupo A formado por 42 pacientes submetidos à ATJ com denervação patelar (PD) e grupo B formado por 42 pacientes submetidos a ATJ sem a denervação (ND). Os resultados foram avaliados utilizando os questionários WOMAC e KSS, além da escala analógica visual da dor (EVA). Também foi avaliada a amplitude de movimento em graus. As condições clínicas pré-operatórias dos dois grupos foram semelhantes. RESULTADOS: Comparando a pontuação do questionário WOMAC, o grupo A apresentou melhores resultados, com media de 27,95 ± 5,89, enquanto o grupo B apresentou média de 33,55 ± 6,23. Melhores resultados foram também observados no KSS para o grupo A, apresentando média de 86,19 ± 7,10, em comparação ao grupo B, com média de 83,07 ± 4,88. Observou-se menor amplitude de flexão do joelho no grupo A, 119,0 ± 10,68 graus, em comparação com o grupo B, com média de 125,5 ± 11,02 graus. Analisando exclusivamente a dor, não foi observada diferença entre a dor referida pelo paciente, de acordo com a escore da escala EVA. CONCLUSÕES: A DP não demonstrou melhores efeitos na redução da dor em comparação com ND na ATJ. No entanto um melhor efeito da denervação nos escores de função, através dos questionários KSS e WOMAC sugerem que a denervação pode ser benéfica neste cenário.

Patellar Resurfacing Versus Circumferential Denervation of the Patella in Total Knee Arthroplasty.

This study compared the rates of anterior knee pain and functional outcomes between resurfaced patellas and non-resurfaced patellas with a circumpatellar denervation. One hundred ten patients who underwent patellar resurfacing or a circumpatellar denervation were evaluated for knee pain and functional outcomes at a minimum of 2 years after total knee arthroplasty. There were no significant differences between the 2 groups regarding Knee Society Scores, anterior knee pain scores, or visual analog scale scores. The groups had similar incidences of anterior knee pain. Most patients reported no to mild effect of anterior knee pain on daily living. Patients in each group reported increased pain with kneeling, squatting, and departing an automobile. Similar proportions of patients were disappointed with their overall outcomes in each group. Circumpatellar denervation and patellar resurfacing during total knee arthroplasty lead to similar incidences of anterior knee pain. [Orthopedics. 2016; 39(5):e1019-e1023.].

Area of Skin Numbness After Total Knee Arthroplasty: Does Minimally Invasive Approach Make Any Difference From Standard Approach?

BACKGROUND: Skin numbness after total knee arthroplasty (TKA) was reported in relation to injury of the infrapatellar branch of saphenous nerve (IPBSN). METHODS: Phase I study: A nonrandomized and nonconsecutive selection of 30 patients undergoing unilateral TKA, using minimally invasive surgery approach, and 30 patients having standard approach were included. Area of skin numbness was periodically evaluated and compared until 1-year follow-up (FU). Phase II study: we dissected 15 normal cadaveric knees and followed the course and distribution of IPBSN. RESULTS: Twenty-nine predominantly female patients in each group completed 1-year FU with no differences in demographic data. Both the groups had significantly improved Knee Society Score clinical and function scores with no statistical differences. The numb areas in both the groups similarly decreased from 2 weeks (51.7 cm2 vs 51.1 cm2) to 1 year (2.1 cm2 vs 2.4 cm2) with similar percentages of no skin numbness at 1 year (69% vs 65%). The IPBSN branched from saphenous nerve before exiting the adductor canal and ran longitudinally and obliquely. It was found as a single nerve in 20%, a 2-branch nerve in 67% and a 3-branch nerve in 13%. All branches crossed the knee midline between superior patellar pole and tibial tubercle. CONCLUSION: Clinical study showed that TKA using minimally invasive surgery approach provided similar area of skin numbness to standard approach. Numbness area gradually decreased at serial FUs in both the groups. The cadaveric study demonstrated that the IPBSN consistently gave no branch passing the knee midline above superior patellar pole.

Is patellar denervation necessary in total knee arthroplasty without patellar resurfacing?

PURPOSE: To conduct a meta-analysis with randomized controlled trials (RCTs) published in full text to determine the effectiveness of patellar denervation (PD) in primary total knee arthroplasty (TKA). METHODS: Literature search was performed in PubMed, Embase, Web of Science and Cochrane Library for information from the earliest date of data collection to February 2015. RCTs comparing the benefits and risks of PD with those of no patellar denervation (NPD) in primary TKAs were included. Statistical heterogeneity was quantitatively evaluated by X(2) test with the significance set P < 0.10 or I (2) > 50 %. RESULTS: Six RCTs consisting of 751 patients were included. The incidences of AKP in PD group and NPD group were 38.3 % (90/235) and 46.3 % (107/231), respectively. Meta-analysis showed significant prevention effect of PD on the incidence of AKP (OR 0.65; 95 % CI 0.42, 1.00; P = 0.05) without significant heterogeneity (I (2) = 44 %, P = 0.15). Our results also indicated that PD was significantly associated with better American Knee Society knee (WMD = 2.50; 95 % CI 0.34, 4.67; P = 0.02) and functional scores (WMD = 4.07; 95 % CI 1.34, 6.80; P = 0.0003) and range of motion (ROM) (WMD = 4.27; 95 % CI 1.95, 6.60; P = 0.0003) compared with NPD. However, there was no significant difference between the two groups no matter in Oxford knee score, patellar score or visual analogue scale at any other time. Complications and revisions did not differ significantly between the two groups. CONCLUSION: This meta-analysis showed that PD in TKAs without patellar resurfacing, compared with NPD, could prevent the incidence of post-operative AKP and improve clinical outcome in KSS and post-operative ROM. Based on the above results, PD was a safe procedure with no significant complications and revision or re-operations. LEVEL OF EVIDENCE: Therapeutic study, Level II.

Circumferential electrocautery of the patella in primary total knee replacement without patellar replacement: a meta-analysis and systematic review.

The purpose of this meta-analysis and systematic review was to identify and assess whether circumferential electrocautery is useful for improving outcomes after primary total knee replacement(TKR). We searched MEDLINE, EMBASE, PubMed, SpringerLink, Web of Knowledge, OVID CINAHL, OVID EBM and Google Scholar and included articles published through January 2014. A total of 6 articles met the inclusion criteria. Of the 776 cases included in the analysis, 388 cases involved patellar denervation, and 388 cases were designated as the control group. The meta-analysis revealed no significant difference in the incidence of anterior knee pain (AKP, p = 0.18) or in the visual analogue scale score (VAS, p = 0.23) between the two groups. In addition, AKSS Function Score indicated no significant difference between the two groups (p = 0.28). However, the OKS (p = 0.02), patellar score (p = 0.01), AKSS-Knee Score (p = 0.004), range of motion (ROM, p < 0.0001) and WOMAC Score (p = 0.0003) indicated that circumpatellarelectrocautery improved clinical outcomes compared with non-electrocautery. The results indicate that circumferential electrocautery of the patella does not significantly improve AKP compared with non-electrocautery techniques but that circumferential electrocautery significantly improves patients' knee function after surgery. Therefore, we believe that circumferential electrocautery is beneficial to the outcome of primary TKR surgery without patellar replacement.

Does patellar denervation reduce post-operative anterior knee pain after total knee arthroplasty?

PURPOSE: The effectiveness of patellar denervation in reducing anterior knee pain and improving patient satisfaction and quality of life after total knee arthroplasty (TKA) is still controversial. A meta-analysis was conducted to try to settle the controversy. METHODS: The electronic databases PubMed, Web of Science, Embase, and Cochrane Library were systematically searched. Of 374 papers identified, seven randomised controlled trials involving 898 patients (983 knees) were eligible for data extraction and meta-analysis. RESULTS: Analysis showed that patellar denervation can significantly improve clinical outcomes for the first 12 months of follow-up after TKA, including anterior knee pain incidence (P = 0.008), visual analogue scale score (P < 0.001), patellar score (P < 0.001), Knee Society Score (P = 0.03), Knee Society Score function score (P = 0.03), and knee range of motion (P = 0.008). However, no statistical significance in outcomes was found between the patellar denervation group and no-denervation group for any of those parameters after 12 months of follow-up. CONCLUSION: The best currently available evidence suggests that patellar denervation can significantly reduce anterior knee pain incidence and improve early clinical outcomes after TKA. However, after a prolonged period of follow-up, this advantage seems to disappear. Even so, the use of patellar denervation in primary TKA is recommended because it is safe and produces good early clinical outcomes. LEVEL OF EVIDENCE: Therapeutic study, Level II.

Patellofemoral resurfacing and patellar denervation in primary total knee arthroplasty.

PURPOSE: To conduct a systematic review and network meta-analysis of randomized controlled trials (RCTs) with the aim of comparing relevant clinical outcomes between patellar denervation, resurfacing and non-resurfacing. METHODS: A database search was performed using PubMed and Scopus search engines. RCTs or quasi-experimental designs comparing clinical outcomes between treatments by a search of articles dated from inception to October 23, 2012. Unstandardized mean difference (UMD) and random effects methods were applied for pooling continuous and dichotomous outcomes, respectively. A longitudinal mixed regression model was used for network meta-analysis to indirectly compare treatment effects. RESULTS: Eighteen of 315 studies identified were eligible. Compared with patellar non-resurfacing, patellar denervation had a UMD that displayed a significant improvement in symptoms with values in pain visual analog score (VAS) and Knee Society Score (KSS) of -0.6 [95% confidence interval (CI) -1.13, -0.25] and 2.55 (95% CI 0.43, 4.68), respectively. The UMD in VAS, KSS, and Knee Function Score (KFS) in patellar resurfacing showed no significant improvement in symptoms when compared to non-resurfacing. Patients who underwent surgery with patellar resurfacing had a lower reoperation rates with pooled relative risks (RRs) of 0.69 (95% CI 0.50, 0.94) when compared to non-resurfacing. The network meta-analysis suggested a benefit of borderline significance for patellar denervation with a pooled RR of 0.63 (95% CI 0.38, 1.03), showing that there is a lower chance of anterior knee pain when compared to non-resurfacing. Patellar resurfacing also displays a significantly lower chance of reoperation with a pooled RR of 0.68 (95% CI 0.50, 0.92) when compared to non-resurfacing. Multiple active treatment comparisons indicated that patellar denervation resulted in greater improvement in KFS than patellar resurfacing. CONCLUSION: This review suggests that either patellar denervation or patellar resurfacing may be selected for the management of the patellofemoral component in total knee replacement. Patellar denervation may help improve postoperative knee function, but does not improve pain when compared to patellar resurfacing.

Effect of patellar denervation on mid-term results after non-resurfaced total knee arthroplasty. A randomised, controlled trial.

UNLABELLED: Aim of this study is to determine the clinical effect of circumpatellar electrocautery on cases undergoing non-resurfaced total knee arthroplasty. PATIENTS AND METHODS: 184 patients undergoing non-resurfaced total knee arthroplasty were included and randomized into two, patient and outcome assessor-blinded, parallel groups: 92 patient in denervation group & 92 patients in no-denervation group. Pre-operative and final most recent follow up's Western Ontario McMaster score and anterior knee pain rating were used for statistical analysis. RESULTS: There was no statistically significant difference between both groups preoperatively in anterior knee pain, WOMAC score, or range of motion. While on all the three parameters there was a statistically significant difference in improvement in favor of denervation group. DISCUSSION: Our study demonstrated that post-operative functional score and anterior knee pain score were significantly better in electrocauterised group. This shows that patellar denervation significantly improve clinical outcome and decreased anterior knee pain in NR-TKA.