After starting an orthopedic practice, a surgeon with a fellowship in mechanically aligned (MA) TKA initiated this study to characterize their learning curve after they switched to unrestricted kinematic alignment (KA) TKA using manual instruments. Accordingly, the present study determined for the inexperienced (IE) surgeon the number of cases required to achieve consistent femoral resections and operating times, and whether the femoral resection accuracy, patient-reported outcome measures (PROMs), and component alignment were different from an experienced (E) surgeon. This prospective cohort study analyzed the IE surgeon’s first 30 TKAs, all performed with KA, and 30 consecutive KA TKAs performed by an E surgeon. The resection accuracy or deviation was the calipered thickness of the distal and posterior medial and lateral femoral resections minus the planned resection thickness, which was the thickness of the corresponding condyle of the femoral component, minus 2 mm for cartilage wear, and 1 mm for the kerf of the blade. Independent observers recorded the femoral resection thickness, operative times, PROMs, and alignment. For each femoral resection, the deviation between three groups of patients containing ten consecutive KA TKAs, was either insignificant (p = 0.695 to 1.000) or within the 0.5 mm resolution of the caliper, which indicated no learning curve. More than three groups were needed to determine the learning curve for the operative time; however, the IE surgeon’s procedure dropped to 77 min for the last 10 patients, which was 20 min longer than the E surgeon. The resection deviations of the IE and E surgeon were comparable, except for the posterolateral femoral resection, which the IE surgeon under-resected by a mean of −0.8 mm (p < 0.0001). At a mean follow-up of 9 and 17 months, the Forgotten Joint Score, Oxford Knee Score, KOOS, and the alignment of the components and limbs were not different between the IE and E surgeon (p ≥ 0.6994). A surgeon that switches to unrestricted KA with manual instruments can determine their learning curve by computing the deviation of the distal and posterior femoral resections from the planned resection. Based on the present study, an IE surgeon could have resection accuracy, post-operative patient outcomes, and component alignment comparable to an E surgeon.

Background: Unrestricted caliper-verified kinematically aligned (KA) TKA restores patient’s prearthritic coronal and sagittal alignments, which have a wide range containing outliers that concern the surgeon practicing mechanical alignment (MA). Therefore, knowing which radiographic parameters are associated with dissatisfaction could help a surgeon decide whether to rely on them as criteria for revising an unhappy patient with a primary KA TKA using MA principles. Hence, we determined whether the femoral mechanical angle (FMA), hip–knee–ankle angle (HKAA), tibial mechanical angle (TMA), tibial slope angle (TSA), and the indicators of patellofemoral tracking, including patella tilt angle (PTA) and the lateral undercoverage of the trochlear resection (LUCTR), are associated with clinical outcome scores. Methods: Forty-three patients with a CT scan and skyline radiograph after a KA TKA with PCL retention and medial stabilized design were analyzed. Linear regression determined the strength of the association between the FMA, HKA angle, PTS, PTA, and LUCTR and the forgotten joint score (FJS), Oxford knee score (OKS), and KOOS Jr score obtained at a mean of 23 months. Results: There was no correlation between the FMA (range 2° varus to −10° valgus), HKAA (range 10° varus to −9° valgus), TMA (range 10° varus to −0° valgus), TSA (range 14° posterior to −4° anterior), PTA (range, −10° medial to 14° lateral), and the LUCTR resection (range 2 to 9 mm) and the FJS (median 83), the OKS (median 44), and the KOOS Jr (median 85) (r = 0.000 to 0.079). Conclusions: Surgeons should be cautious about using postoperative FMA, HKAA, TMA, TSA, PTA, and LUCTR values within the present study’s reported ranges to explain success and dissatisfaction after KA TKA.

Fascial herniations of the leg occur when an intracompartmental leg muscle protrudes through weaknesses in the overlying fascial sheath. These fascial defects may be congenital or acquired from trauma involving penetrating injuries to the fascia. Increases in intracompartmental pressure, often resulting from muscular hypertrophy, can lead to muscular herniation through the weakened fascia. This may present as a leg mass which is often misdiagnosed as a hematoma, varicosity, or soft-tissue mass, leading to significant delays in treatment. We present a case of a peroneus brevis herniation in a 25-year-old male competitive runner with a history of a tibial stress fracture. This patient was referred to the senior author following three years of lateral leg pain worsened by activity. After confirmation of the herniation on MRI, the patient underwent a limited lateral compartment fasciotomy with complete resolution of symptoms at a six-month follow-up. This case demonstrates common pitfalls in the diagnosis of fascial herniations in refractory leg pain of runners. A comprehensive knowledge of this diagnosis and its risk factors can aid in the successful treatment of this patient cohort.

Varicella-zoster virus (VZV) is a member of the alpha-herpesvirus family, which can occasionally cause severe neurological complications such as encephalitis. In this case report, we discuss a rare finding of VZV encephalitis in which an immunocompetent pediatric patient, vaccinated against varicella, presented with altered mental status and no vesicular rash. A 15-year-old male presented to the Emergency Department with progressively worsening altered mental status over the past three days. The patient's mother stated that he was exhibiting frequent memory lapses as well as the sudden loss of the ability to play the piano. After admission to the pediatric general floor, lumbar puncture was performed and cerebrospinal fluid analysis returned positive for VZV, confirmed by polymerase chain reaction. The patient was then started on intravenous (IV) acyclovir at a dose of 650 mg every 8 hours to treat VZV-induced encephalitis. While the patient continued to have intermittent episodes of confusion and headaches, his overall condition improved, and by day 4, he was able to resume playing the piano and ukulele. The patient was discharged on day 8 with no home medications, and a follow-up with this primary care physician was scheduled. This patient is one of only four recorded cases of VZV encephalitis in immunocompetent children. It is extremely rare to encounter pediatric patients with this diagnosis and, as such, can elude physicians when developing differential diagnoses. If VZV is suspected, a lumbar puncture should be performed promptly, and, if confirmed, IV acyclovir should be started. Furthermore, this case highlights the need for future research with regard to VZV and potential predisposing factors in immunocompetent patients.

Peritonitis is inflammation of the peritoneum that can arise from a number of complications affecting the lining of the abdominal wall and organs. Acute abdomen and peritonitis is a rare complication in a previously healthy woman following a seemingly uncomplicated normal full-term vaginal delivery. We report such a case in a 20-year-old gravida 2 para 2 (G2P2) woman of Guatemalan descent, who presented nine days postpartum following an uncomplicated delivery, to the emergency room with acute abdomen and associated systemic inflammatory reaction. Interventional radiology paracentesis was performed, yielding a milky, purulent peritoneal fluid with no visible organisms and negative cultures. Antibiotics and paracentesis were insufficient in managing her condition, which continued to worsen over the course of several days. Given her continued deterioration despite clinical intervention, she underwent an exploratory laparotomy and peritoneal lavage along with continued broad-spectrum antibiotics. Cultures continued to be negative but operative findings included diffuse fibrinous peritonitis with no obvious abscess or perforated abdominal viscus. Following surgical laparotomy, she recovered fully without any complications. We review the available literature regarding peritonitis, discuss its management, and speculate as to its cause in this case.