Fabella Syndrome and Common Peroneal Neuropathy following Total Knee Arthroplasty

Case. A 62-year-old man presented with persistent lateral knee pain 15 months following an uncomplicated total knee arthroplasty. There was a tendinous snapping structure over the lateral aspect of the knee in deep flexion with positive Tinel’s sign over the fibular head. The patient underwent an uncomplicated flabella excision. The patient was cleared to return to work and full duty at two months postoperatively. Conclusion. Flabella syndrome is a rare but increasingly common mechanism of persistent lateral knee pain following total knee arthroplasty. Surgeons should be aware of this etiology of persistent lateral knee pain and offer treatment modalities to address this pathology.

Lateral Knee Pain Favors the Diagnosis of Anterior Cruciate Ligament Injury and its Postoperative Assessment Potentially Contributes in Treatment Follow- Up; A Pilot Study

Background: Anterior Cruciate Ligament (ACL) reconstruction is a standard technique for treatment of patients with an ACL tear. According to clinical observations, lateral knee pain is highly associated with a teared ACL, this correlation so far has remained unnoticed in the literature. In this study, we aim to investigate the relationship of lateral knee pain with diagnosis of torn ACL.Methods: This pilot study was conducted on 30 candidates of ACL reconstruction. The participants underwent surgical reconstruction of ACL; Then Visual Analogue Scale (VAS) was used to measure pain at three time points of preoperative, first and second postoperative visits. Results: A total of 26 participants (86.7%) were male with a mean age of 27.3±5.06 years. The results demonstrated that the intensity of lateral knee pain felt by the subjects significantly diminished during subsequent postoperative referrals (P-value<0.001). However, other variables including sex, age, and type of surgery (bone-patella tendon-bone and hamstring tendon) caused no significant difference in terms of pain reduction (p>0.05). Conclusions: Lateral knee pain is likely related with anterior cruciate ligament tear and favors its diagnosis. Also, the evaluation of lateral knee pain may contribute in Anterior Cruciate Ligament reconstruction (ACLR) monitoring in the follow-up stage.

Current Clinical Concepts: Synthesizing the Available Evidence for Improved Clinical Outcomes in Iliotibial Band Impingement Syndrome

The current paradigm of insidious lateral knee pain involving the iliotibial band (ITB) in repetitive knee-flexion activities has been termed ITB friction syndrome since 1975. The original model for ITB pain was based on a limited or incorrect understanding of the relevant anatomy, biomechanics, and tissue science, which gradually led to a plethora of frustrating and ineffective interventional strategies. Mounting evidence from arthroscopic, cadaveric, and biomechanical studies, as well as from diagnostic imaging and histologic reports, has helped deconstruct this long-held paradigm for ITB-related pathology and treatment. By outlining the historical paradigm for our understanding of ITB pain and gathering newer evidence through extensive research, I will synthesize the available data in this clinical update to present an updated, more informed model for understanding insidious-onset ITB-related pathology and treating patients. The result is called ITB impingement syndrome.

Anatomical study of the proximal tibiofibular ligaments using ultrasound

Objectives No description of the proximal tibiofibular (PTF) ligaments by means of high ultrasound has yet been reported in the literature. The purpose of this study was to assess whether ultrasound may allow the assessment of these ligaments. Methods This study was initially undertaken in three cadaveric knees, followed by an ultrasound study performed by two musculoskeletal radiologists working in consensus of 52 patients without history of trauma or surgery of the knee, and without lateral knee pain. The visibility, echogenicity, length and thickness of the PTF ligaments were assessed. Results Regarding the anterior PTF ligament, the superior bundle and the upper and lower middle bundles were clearly seen in 42.3%, 100% and 75% of the knees, respectively. Regarding the posterior PTF ligament, the superior and middle bundles were clearly seen in 88.4% and 51.9% of the knees, respectively. The echo-anatomy of these ligaments and the probe positioning allowing their best depiction were described in this study. Conclusion Most of the PTF ligaments can be visualized by means of ultrasound. This possible assessment may have clinical applications, particularly in patients with lateral knee pain.

Iliotibial Band Pathology: Synthesizing the Available Evidence for Clinical Progress

The current paradigm of practice concerning insidious lateral knee pain involving the iliotibial band in repetitive knee flexion activities has been presented as iliotibial band friction syndrome since 1974. Renne's original model for ITB pain was based on a limited or incorrect understanding of the relevant anatomy, biomechanics, and tissue science, which gradually led to a plethora of frustrating and ineffective interventional strategies. Mounting evidence from arthroscopic, cadaveric and biomechanical studies, as well as from diagnostic imaging and histology reports helps deconstruct this long-held paradigm for ITB related pathology and treatment. Using an archeological approach to gather relevant evidence, this clinical update synthesizes the available data in order to present an updated, more informed model for understanding and treating insidious onset related ITB related pathology. The result is a new, more informed paradigm called Iliotibial Band Impingement Syndrome.

Effect of Q-factor manipulation via pedal spacers on lower limb frontal plane kinematics during cycling

Anecdotal evidence suggests that frontal plane kinematics of the lower extremity are an important aspect of bicycle fit, however, frontal plane adjustments are often overlooked during common fitting procedures. The purpose of this study was to manipulate Q-factor width via pedal spacers to determine their influence on frontal plane kinematics of the hip, knee, and ankle during cycling. Twenty-four young healthy recreational cyclists (12 female) completed five minutes of pedaling at their preferred cadence and power output under three stance widths conditions: no spacer, 20 mm spacer, and 30 mm spacer. For each participant, the pedaling cadence and power output were kept identical for all experimental conditions. Lower extremity marker position data were captured at 250 Hz for the last two minutes of each condition. Sixty consecutive crank cycles were analyzed to identify maximum and minimum hip, knee, and ankle angles in the frontal plane. With an increase in Q-factor, hip and knee maximum abduction angles increased and maximum adduction angles decreased. With increase in Q-factor from no spacer to 20 mm spacer condition, hip abduction increased by 0.8o (∆10%; p<0.001) whereas hip abduction decreased by 0.9o (∆23%; p<0.001) and similarly, knee abduction increased by 1.2o (∆60%; p=0.002) whereas knee abduction decreased by 1.1o (∆18%; p=0.003). And with increase in Q-factor from no spacer to 30 mm spacer condition, hip abduction increased by 1.4o (∆18%; p<0.001) and hip adduction decreased by 1.6o (∆40%; p<0.001) and similarly, knee abduction increased by 1.8o (∆86%; p<0.001) and knee adduction decreased by 2.1o (∆35%; p<0.001). Maximum and minimum ankle angles were not affected by the stance width conditions (p>0.05). Pedal spacers are an effective way of manipulating Q-factor and frontal plane kinematics of the hip and knee and could help cyclists experiencing medial or lateral knee pain.