Rodilla/Knee: aprovechar que la vascularización de la rótula va en parte por medial

Quantitative assessment of patellar vascularity following bone-patellar tendon-bone autograft harvest for ACL reconstruction.

Jones KJ, Lazaro LE, Taylor SA, Pardee NC, Dyke JP, Hannafin JA, Warren RF, Lorich DG

Knee Surg Sports Traumatol Arthrosc. 2015 Jan 22. [Epub ahead of print]

Abstract

PURPOSE: 

Recent anatomic studies have suggested that the dominant arterial supply of the patella enters through the inferior pole. Based upon these findings, we hypothesized that bone-patellar tendon-bone graft harvest can significantly diminish patellar vascularity.

METHODS: 

Nine matched pair cadaveric knee specimens (mean age 47.4 years) were dissected and cannulated. A single knee was selected to undergo routine graft harvest, and the contralateral knee was left intact to serve as a control. Gadolinium was injected, and magnetic resonance imaging (MRI) signal enhancement was quantified to determine differences in uptake. Each matched pair was subsequently injected with a urethane polymer compound and dissected to correlate vessel disruption with MRI findings.

RESULTS: 

We identified two predominating patterns of vessel entry. In one pattern, the vessel entered the inferomedial aspect (five o'clock/right, seven o'clock/left) of the patella and was disrupted by graft harvest in 2/9 (22.2 %) pairs. In the second pattern, the vessel entered further medial (four o'clock/right, eight o'clock/left) and was not disrupted (7/9, 78.8 %). The mean decrease in gadolinium uptake following disruption of the predominant vessel measured 56.2 % (range 42.6-69.5 %) compared to an average decrease of 18.3 % (range 7.1-29.1 %) when the dominant arterial supply to the inferior pole remained intact (p < 0.04).

CONCLUSION: 

Medial entry of the predominant vessel precluded vessel disruption. Disruption of the dominant arterial supply can result in a significant decrease in patellar vascularity. Modification of graft harvest techniques and areas of surgical dissection should be explored to minimize vascular insult. Further correlation with clinical studies/outcomes is necessary to determine a potential association between vascular insult and anterior knee pain.

Rodilla/Knee/Knie/Genou: Es fácil dañar las ramas del safeno al extraer los tendones

The Course And Distribution Of The Infra Patellar Nerve In Relation To Acl Reconstruction

T. Walshaw , S.V. Karuppiah , I. Stewart

The Knee

Publication date: Available online 26 November 2014

Introduction
A common complication after ACL (anterior cruciate ligament reconstruction) is injury to the infra-patellar branch of the saphenous nerve (IPBSN). Very little about its origin and course of this nerve has been described. The aim of this study was to understand the course of IPBSN in relation to surgery around the knee.

Materials and method
The course of the nerve was dissected and traced in 25 knees from 14 cadaveric knees (10 male; 4 female). An incision was made posterior to the medial condyle of the tibia and continued deeper towards the saphenous nerve which is located under the sartorius muscle. The sapheneous nerve branch was then followed distally supply the anterior leg (IPBSN). The relationship of saphenous nerve and IPBSN to each other and the hamstrings were recorded

Results
Four paths of IPBSN, in relation to the Sartorius muscle, were identified: (1) posterior - inferior posterior border of the muscle, (2) transmuscular - penetrating through the muscle, (3) anterior - anterior border of the muscle, (4) posterior patellar - posterior of the muscle at the level of the patellar bone and (5) combined The posterior pathway of IPSBN was the most common (57%) and had the closest proximity to the tendons of semintendinosus and gracilis muscles. The terminal branches of the IPSBN crossed over the patella tendon in every dissection.

Conclusions
A posterior path IPBSN is more prone to damage during a tendon harvest due to its proximity to the gracilis and semitendinosus muscle tendons. 

Rodilla/Knee/Knie/Genou: ¿Qué haces si se te cae al suelo la plastia reconstruyendo un LCA?

When the tendon autograft drops accidently on the floor: A study about bacterial contamination and antiseptic efficacy

O. Barbier, J. Danis, G. Versier, D. Ollat

The Knee

Available online 11 August 2014

Abstract

Background

Inadvertent contamination of the autograft could occur during ACL reconstruction if the autograft drops on the floor during surgery. A study was undertaken to determine the incidence of contamination when a graft dropped on the operating room floor and the efficacy of antimicrobial solutions to decontaminate it.

Methods

Samples from 25 patients undergoing ACL reconstruction with a hamstring tendon were sectioned and dropped onto the floor. Cultures were taken after immersion in an antiseptic solutions (a chlorhexidine gluconate solution (group 1), a povidone-iodine solution (group 2), a sodium-hypochlorite solution (group 3). A fourth piece (group 0) was cultured without being exposed to any solution. Cultures of a floor swab were taken at the same time.

Results

The floor swab cultures were positive in 96% of cases. The rate of contamination was 40% in group 0, 8% in group 1, 4% in group 2, and 16% in group 3. There was a significant difference between groups 1–2 and 0 (p < 0,05) but not between group 3 and 0.

Conclusion

Immersing a graft dropped onto the floor during surgery into in a chlorhexidine gluconate solution or povidone-iodine solution significantly reduces contamination of the graft. Soaking of the hamstring autograft in one of theses solutions is recommended in case of inadvertent contamination.

Clinical relevance: laboratory investigation (level 2)

 

Rodilla/Knee/Knie: Cuidado al interpretar la RMN ante el fracaso de una ligamentoplastia

A Radiographic Assessment of Failed Anterior Cruciate Ligament Reconstruction: Can Magnetic Resonance Imaging Predict Graft Integrity?

Waltz RA, Solomon DJ, Provencher MT

Am J Sports Med 2014 May 12

Abstract

BACKGROUND: Magnetic resonance imaging (MRI) showing an "intact" anterior cruciate ligament (ACL) graft may not correlate well with examination findings. Reasons for an ACL graft dysfunction may be from malpositioned tunnels, deficiency of secondary stabilizers, repeat injuries, or a combination of factors. 

PURPOSE: To evaluate the concordance/discordance of an ACL graft assessment between an arthroscopic evaluation, physical examination, and MRI and secondarily to evaluate the contributing variables to discordance. 

STUDY DESIGN: Case series; Level of evidence, 4.

METHODS: A total of 50 ACL revisions in 48 patients were retrospectively reviewed. The ACL graft status was recorded separately based on Lachman and pivot-shift test data, arthroscopic findings from operative reports, and MRI evaluation and was categorized into 3 groups: intact, partial tear, or complete tear. Two independent evaluators reviewed all of the preoperative radiographs and MRI scans, and interrater and intrarater reliability were evaluated. Concordance and discordance between a physical examination, arthroscopic evaluation, and MRI evaluation of the ACL graft were calculated. Graft position and type, mechanical axis, collateral ligament injuries, chondral and meniscal injuries, and mechanism of injury were evaluated as possible contributing factors using univariate and multivariate analyses. Sensitivity and specificity of MRI to detect a torn ACL graft and meniscal and chondral injuries on arthroscopic evaluation were calculated. 

RESULTS: The interobserver and intraobserver reliability for the MRI evaluation of the ACL graft were moderate, with combined κ values of .41 and .49, respectively. The femoral tunnel position was vertical in 88% and anterior in 46%. On MRI, the ACL graft was read as intact in 24%; however, no graft was intact on arthroscopic evaluation or physical examination. The greatest discordance was between the physical examination and MRI, with a rate of 52%. An insidious-onset mechanism of injury was significantly associated with discordance between MRI and arthroscopic evaluation of the ACL (P = .0003) and specifically with an intact ACL graft on MRI (P = .0014). The sensitivity and specificity of MRI to detect an ACL graft tear were 60% and 87%, respectively. 

CONCLUSION: Caution should be used when evaluating a failed ACL graft with MRI, especially in the absence of an acute mechanism of injury, as it may be unreliable and inconsistent.